Price fraction: Difference between revisions

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Revision as of 13:55, 14 April 2024

A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.

Task

Given a floating point value between 0.00 and 1.00, rescale according to the following table:

>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00

11l

Translation of: Python

F bisect_right(a, x)
   V lo = 0
   V hi = a.len
   L lo < hi
      V mid = (lo + hi) I/ 2
      I x < a[mid]
         hi = mid
      E
         lo = mid + 1
   R lo

V _cin  = [0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01]
V _cout = [0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00]
F pricerounder(pricein)
   R :_cout[bisect_right(:_cin, pricein)]

L(i) 0..10
   print(‘#.2 #.2’.format(i / 10, pricerounder(i / 10)))

Output:

0.00 0.10
0.10 0.18
0.20 0.32
0.30 0.44
0.40 0.54
0.50 0.62
0.60 0.70
0.70 0.78
0.80 0.86
0.90 0.94
1.00 1.00

Action!

DEFINE COUNT="20"
BYTE ARRAY levels=[6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101]
BYTE ARRAY values=[10 18 26 32 38 44 50 54 58 62 66 70 74 78 82 86 90 94 98 100]

PROC PrintValue(BYTE v)
  PrintB(v/100) Put('.)
  v=v MOD 100
  PrintB(v/10)
  v=v MOD 10
  PrintB(v)
RETURN

BYTE FUNC Map(BYTE v)
  BYTE i

  FOR i=0 TO COUNT-1
  DO
    IF v<levels(i) THEN
      RETURN (values(i))
    FI
  OD
RETURN (v)

PROC Main()
  BYTE i,v

  FOR i=0 TO 100
  DO
    v=Map(i)
    PrintValue(v)
    IF i MOD 5=4 THEN
      PutE()
    ELSE
      Put(' )
    FI
  OD
RETURN

Output:

Screenshot from Atari 8-bit computer

0.10 0.10 0.10 0.10 0.10
0.10 0.18 0.18 0.18 0.18
0.18 0.26 0.26 0.26 0.26
0.26 0.32 0.32 0.32 0.32
0.32 0.38 0.38 0.38 0.38
0.38 0.44 0.44 0.44 0.44
0.44 0.50 0.50 0.50 0.50
0.50 0.54 0.54 0.54 0.54
0.54 0.58 0.58 0.58 0.58
0.58 0.62 0.62 0.62 0.62
0.62 0.66 0.66 0.66 0.66
0.66 0.70 0.70 0.70 0.70
0.70 0.74 0.74 0.74 0.74
0.74 0.78 0.78 0.78 0.78
0.78 0.82 0.82 0.82 0.82
0.82 0.86 0.86 0.86 0.86
0.86 0.90 0.90 0.90 0.90
0.90 0.94 0.94 0.94 0.94
0.94 0.98 0.98 0.98 0.98
0.98 1.00 1.00 1.00 1.00
1.00

Ada

type Price is delta 0.01 digits 3 range 0.0..1.0;
function Scale (Value : Price) return Price is
   X : constant array (1..19) of Price :=
          (  0.06, 0.11, 0.16, 0.21, 0.26,  0.31, 0.36, 0.41, 0.46, 0.51,
             0.56, 0.61, 0.66, 0.71, 0.76,  0.81, 0.86, 0.91, 0.96
          );
   Y : constant array (1..20) of Price :=
          (  0.10, 0.18, 0.26, 0.32, 0.38,  0.44, 0.50, 0.54, 0.58, 0.62,
             0.66, 0.70, 0.74, 0.78, 0.82,  0.86, 0.90, 0.94, 0.98, 1.0
          );
   Low    : Natural := X'First;
   High   : Natural := X'Last;
   Middle : Natural;
begin
   loop
      Middle := (Low + High) / 2;
      if Value = X (Middle) then
         return Y (Middle + 1);
      elsif Value < X (Middle) then
         if Low = Middle then
            return Y (Low);
         end if;
         High := Middle - 1;
      else
         if High = Middle then
            return Y (High + 1);
         end if;
         Low := Middle + 1;
      end if;
   end loop;
end Scale;

The solution uses fixed point type to prevent rounding and representation issues. With the above declarations a full coverage test:

with Ada.Text_IO; use Ada.Text_IO;
procedure Test_Price_Fraction is
   -- Put the declarations here
   Value : Price := Price'First;
begin
   loop
      Put_Line (Price'Image (Value) & "->" & Price'Image (Scale (Value)));
      exit when Value = Price'Last;
      Value := Price'Succ (Value);
   end loop;
end Test_Price_Fraction;

Output:

 0.00-> 0.10
 0.01-> 0.10
 0.02-> 0.10
 0.03-> 0.10
 0.04-> 0.10
 0.05-> 0.10
 0.06-> 0.18
 0.07-> 0.18
 0.08-> 0.18
 0.09-> 0.18
 0.10-> 0.18
 0.11-> 0.26
 0.12-> 0.26
 0.13-> 0.26
 0.14-> 0.26
 0.15-> 0.26
 0.16-> 0.32
 0.17-> 0.32
 0.18-> 0.32
 0.19-> 0.32
 0.20-> 0.32
 0.21-> 0.38
 0.22-> 0.38
 0.23-> 0.38
 0.24-> 0.38
 0.25-> 0.38
 0.26-> 0.44
 0.27-> 0.44
 0.28-> 0.44
 0.29-> 0.44
 0.30-> 0.44
 0.31-> 0.50
 0.32-> 0.50
 0.33-> 0.50
 0.34-> 0.50
 0.35-> 0.50
 0.36-> 0.54
 0.37-> 0.54
 0.38-> 0.54
 0.39-> 0.54
 0.40-> 0.54
 0.41-> 0.58
 0.42-> 0.58
 0.43-> 0.58
 0.44-> 0.58
 0.45-> 0.58
 0.46-> 0.62
 0.47-> 0.62
 0.48-> 0.62
 0.49-> 0.62
 0.50-> 0.62
 0.51-> 0.66
 0.52-> 0.66
 0.53-> 0.66
 0.54-> 0.66
 0.55-> 0.66
 0.56-> 0.70
 0.57-> 0.70
 0.58-> 0.70
 0.59-> 0.70
 0.60-> 0.70
 0.61-> 0.74
 0.62-> 0.74
 0.63-> 0.74
 0.64-> 0.74
 0.65-> 0.74
 0.66-> 0.78
 0.67-> 0.78
 0.68-> 0.78
 0.69-> 0.78
 0.70-> 0.78
 0.71-> 0.82
 0.72-> 0.82
 0.73-> 0.82
 0.74-> 0.82
 0.75-> 0.82
 0.76-> 0.86
 0.77-> 0.86
 0.78-> 0.86
 0.79-> 0.86
 0.80-> 0.86
 0.81-> 0.90
 0.82-> 0.90
 0.83-> 0.90
 0.84-> 0.90
 0.85-> 0.90
 0.86-> 0.94
 0.87-> 0.94
 0.88-> 0.94
 0.89-> 0.94
 0.90-> 0.94
 0.91-> 0.98
 0.92-> 0.98
 0.93-> 0.98
 0.94-> 0.98
 0.95-> 0.98
 0.96-> 1.00
 0.97-> 1.00
 0.98-> 1.00
 0.99-> 1.00
 1.00-> 1.00

ALGOL 68

Translation of: C

- note: This specimen retains the original C coding style.

Works with: ALGOL 68 version Revision 1 - no extensions to language used

Works with: ALGOL 68G version Any - tested with release 1.18.0-9h.tiny

main:
(
    # Just get a random price between 0 and 1 #
    # srand(time(NIL)); #
    REAL price := random;
    REAL tops := 0.06;
    REAL std val := 0.10;

    # Conditionals are a little odd here "(price-0.001 < tops AND
    price+0.001 > tops)" is to check if they are equal. Stupid
    C floats, right?   :) #
    WHILE ( price>tops OR (price-0.001 < tops AND price+0.001 > tops) ) AND tops<=1.01
    DO
        tops+:=0.05;

        IF std val < 0.26 THEN
                std val +:= 0.08
        ELIF std val < 0.50 THEN
                std val +:= 0.06
        ELSE
                std val +:= 0.04
        FI;

        IF std val > 0.98 THEN
                std val := 1.0
        FI
    OD;

    printf(($"Value :   "z.2dl,"Converted to standard :   "z.2dl$, price, std val))
)

Output:

Value :   0.38
Converted to standard :   0.54

AppleScript

Procedural

The task description doesn't make a lot of sense, implying that the pharmacist charges no more than 1.00 for his wares and that even whole-number prices are nudged by 0.10 and odd ones aren't. This offering takes any decimal currency value and standardises just the fractional part:

-- This handler just returns the standardised real value. It's up to external processes to format it for display.

on standardisePrice(input)
    set integerPart to input div 1.0
    set fractionalPart to input mod 1.0
    
    if (fractionalPart is 0.0) then
        return input as real
    else if (fractionalPart < 0.06) then
        return integerPart + 0.1
    else if (fractionalPart < 0.16) then
        return integerPart + 0.18 + (fractionalPart - 0.06) div 0.05 * 0.08
    else if (fractionalPart < 0.36) then
        return integerPart + 0.32 + (fractionalPart - 0.16) div 0.05 * 0.06
    else if (fractionalPart < 0.96) then
        return integerPart + 0.54 + (fractionalPart - 0.36) div 0.05 * 0.04
    else
        return integerPart + 1.0
    end if
end standardisePrice

-- Test code:
set originals to {}
set standardised to {}
repeat 20 times
    set price to (random number 100) / 100
    set end of originals to text 2 thru -2 of ((price + 10.001) as text)
    set end of standardised to text 2 thru -2 of ((standardisePrice(price) + 10.001) as text)
end repeat

set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to ", "
set output to linefeed & "Originals:    " & originals & linefeed & "Standardised: " & standardised
set AppleScript's text item delimiters to astid
return output

Output:

"
Originals:    0.49, 0.79, 1.00, 0.83, 0.99, 0.23, 0.12, 0.28, 0.72, 0.37, 0.95, 0.51, 0.43, 0.52, 0.84, 0.89, 0.48, 0.48, 0.30, 0.01
Standardised: 0.62, 0.86, 1.00, 0.90, 1.00, 0.38, 0.26, 0.44, 0.82, 0.54, 0.98, 0.66, 0.58, 0.66, 0.90, 0.94, 0.62, 0.62, 0.44, 0.10"

An alternative that would save editing the handler in the event of the government department changing its directive would be to feed it a conversion table of up-to and standardised prices stored elsewhere.

-- This handler just returns the standardised real value. It's up to external processes to format it for display.

on standardisePrice(input, table)
    set integerPart to input div 1.0
    set fractionalPart to input mod 1.0
    
    if (fractionalPart is 0.0) then return input as real
    repeat with thisEntry in table
        if (fractionalPart ≤ beginning of thisEntry) then return integerPart + (end of thisEntry)
    end repeat
end standardisePrice

-- Test code:
-- The conceit here is that the conversion table has been obtained from a file or from a spreadsheet application.
set table to {{0.05, 0.1}, {0.1, 0.18}, {0.15, 0.26}, {0.2, 0.32}, {0.25, 0.38}, {0.3, 0.44}, {0.35, 0.5}, {0.4, 0.54}, {0.45, 58}, {0.5, 0.62}, {0.55, 0.66}, {0.6, 0.7}, {0.65, 0.74}, {0.7, 0.78}, {0.75, 0.82}, {0.8, 0.86}, {0.85, 0.9}, {0.9, 0.94}, {0.95, 0.98}, {0.99, 1.0}}

set originals to {}
set standardised to {}
repeat 20 times
    set price to (random number 100) / 100
    set end of originals to text 2 thru -2 of ((price + 10.001) as text)
    set end of standardised to text 2 thru -2 of ((standardisePrice(price, table) + 10.001) as text)
end repeat

set astid to AppleScript's text item delimiters
set AppleScript's text item delimiters to ", "
set output to linefeed & "Originals:    " & originals & linefeed & "Standardised: " & standardised
set AppleScript's text item delimiters to astid
return output

Output:

"
Originals:    0.92, 0.86, 0.10, 0.40, 0.00, 0.34, 0.44, 0.77, 0.67, 0.19, 1.00, 0.02, 0.49, 0.40, 0.61, 0.91, 0.85, 0.54, 0.01, 0.04
Standardised: 0.98, 0.94, 0.18, 0.54, 0.00, 0.50, 8.00, 0.86, 0.78, 0.32, 1.00, 0.10, 0.62, 0.54, 0.74, 0.98, 0.90, 0.66, 0.10, 0.10"

Functional

---------------------- PRICE FRACTION ----------------------

property table : [¬
    {0.06, 0.1}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38}, ¬
    {0.31, 0.44}, {0.36, 0.5}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62}, ¬
    {0.56, 0.66}, {0.61, 0.7}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, ¬
    {0.81, 0.86}, {0.86, 0.9}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.0}]


-- rescaled :: [(Float, Float)] -> Float -> Float
on rescaled(table)
    script
        on |λ|(x)
            if 0 > x or 1.01 < x then
                |Left|("Out of range.")
            else
                |Right|(snd(my head(dropWhile(compose(ge(x), my fst), table))))
            end if
        end |λ|
    end script
end rescaled


--------------------------- TEST ---------------------------
on run
    fTable("Price adjustments:\n", ¬
        showReal(2), either(identity, showReal(2)), ¬
        rescaled(table), enumFromThenTo(-0.05, 0, 1.1))
end run


----------- GENERAL AND REUSABLE PURE FUNCTIONS ------------

-- Left :: a -> Either a b
on |Left|(x)
    {type:"Either", |Left|:x, |Right|:missing value}
end |Left|


-- Right :: b -> Either a b
on |Right|(x)
    {type:"Either", |Left|:missing value, |Right|:x}
end |Right|


-- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
on compose(f, g)
    script
        property mf : mReturn(f)
        property mg : mReturn(g)
        on |λ|(x)
            mf's |λ|(mg's |λ|(x))
        end |λ|
    end script
end compose


-- drop :: Int -> [a] -> [a]
-- drop :: Int -> String -> String
on drop(n, xs)
    set c to class of xs
    if script is not c then
        if string is not c then
            if n < length of xs then
                items (1 + n) thru -1 of xs
            else
                {}
            end if
        else
            if n < length of xs then
                text (1 + n) thru -1 of xs
            else
                ""
            end if
        end if
    else
        take(n, xs) -- consumed
        return xs
    end if
end drop


-- dropWhile :: (a -> Bool) -> [a] -> [a]
-- dropWhile :: (Char -> Bool) -> String -> String
on dropWhile(p, xs)
    set lng to length of xs
    set i to 1
    tell mReturn(p)
        repeat while i ≤ lng and |λ|(item i of xs)
            set i to i + 1
        end repeat
    end tell
    drop(i - 1, xs)
end dropWhile


-- either :: (a -> c) -> (b -> c) -> Either a b -> c
on either(lf, rf)
    script
        on |λ|(e)
            if missing value is |Left| of e then
                tell mReturn(rf) to |λ|(|Right| of e)
            else
                tell mReturn(lf) to |λ|(|Left| of e)
            end if
        end |λ|
    end script
end either


-- enumFromThenTo :: Int -> Int -> Int -> [Int]
on enumFromThenTo(x1, x2, y)
    set xs to {}
    set d to x2 - x1
    set v to x1
    repeat until v ≥ y
        set end of xs to v
        set v to d + v
    end repeat
    return xs
end enumFromThenTo


-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
    tell mReturn(f)
        set v to startValue
        set lng to length of xs
        repeat with i from 1 to lng
            set v to |λ|(v, item i of xs, i, xs)
        end repeat
        return v
    end tell
end foldl


-- fst :: (a, b) -> a
on fst(tpl)
    if class of tpl is record then
        |1| of tpl
    else
        item 1 of tpl
    end if
end fst


-- fTable :: String -> (a -> String) -> (b -> String) -> (a -> b) -> [a] -> String
on fTable(s, xShow, fxShow, f, xs)
    set ys to map(xShow, xs)
    set w to maximum(map(my |length|, ys))
    script arrowed
        on |λ|(a, b)
            justifyRight(w, space, a) & " -> " & b
        end |λ|
    end script
    s & linefeed & unlines(zipWith(arrowed, ¬
        ys, map(compose(fxShow, f), xs)))
end fTable


-- ge :: Ord a => a -> a -> Bool
on ge(a)
    -- True if a is greater
    -- than or equal to b.
    script
        on |λ|(b)
            a ≥ b
        end |λ|
    end script
end ge


-- head :: [a] -> a
on head(xs)
    if xs = {} then
        missing value
    else
        item 1 of xs
    end if
end head


-- identity :: a -> a
on identity(x)
    -- The argument unchanged.
    x
end identity


-- justifyLeft :: Int -> Char -> String -> String
on justifyLeft(n, cFiller, strText)
    if n > length of strText then
        text 1 thru n of (strText & replicate(n, cFiller))
    else
        strText
    end if
end justifyLeft


-- justifyRight :: Int -> Char -> String -> String
on justifyRight(n, cFiller, strText)
    if n > length of strText then
        text -n thru -1 of ((replicate(n, cFiller) as text) & strText)
    else
        strText
    end if
end justifyRight


-- length :: [a] -> Int
on |length|(xs)
    set c to class of xs
    if list is c or string is c then
        length of xs
    else
        (2 ^ 29 - 1) -- (maxInt - simple proxy for non-finite)
    end if
end |length|


-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
    -- The list obtained by applying f
    -- to each element of xs.
    tell mReturn(f)
        set lng to length of xs
        set lst to {}
        repeat with i from 1 to lng
            set end of lst to |λ|(item i of xs, i, xs)
        end repeat
        return lst
    end tell
end map


-- max :: Ord a => a -> a -> a
on max(x, y)
    if x > y then
        x
    else
        y
    end if
end max


-- maximum :: Ord a => [a] -> a
on maximum(xs)
    script
        on |λ|(a, b)
            if a is missing value or b > a then
                b
            else
                a
            end if
        end |λ|
    end script
    
    foldl(result, missing value, xs)
end maximum


-- min :: Ord a => a -> a -> a
on min(x, y)
    if y < x then
        y
    else
        x
    end if
end min


-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
    -- 2nd class handler function lifted into 1st class script wrapper. 
    if script is class of f then
        f
    else
        script
            property |λ| : f
        end script
    end if
end mReturn


-- Egyptian multiplication - progressively doubling a list, appending
-- stages of doubling to an accumulator where needed for binary 
-- assembly of a target length
-- replicate :: Int -> a -> [a]
on replicate(n, a)
    set out to {}
    if 1 > n then return out
    set dbl to {a}
    
    repeat while (1 < n)
        if 0 < (n mod 2) then set out to out & dbl
        set n to (n div 2)
        set dbl to (dbl & dbl)
    end repeat
    return out & dbl
end replicate


-- showReal :: Num b => Int -> b -> String
on showReal(n)
    script
        on |λ|(x)
            set {l, r} to splitOn(".", (x as real) as string)
            l & "." & justifyLeft(n, "0", r)
        end |λ|
    end script
end showReal


-- snd :: (a, b) -> b
on snd(tpl)
    if class of tpl is record then
        |2| of tpl
    else
        item 2 of tpl
    end if
end snd


-- splitOn :: String -> String -> [String]
on splitOn(pat, src)
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, pat}
    set xs to text items of src
    set my text item delimiters to dlm
    return xs
end splitOn


-- str :: a -> String
on str(x)
    x as text
end str


-- take :: Int -> [a] -> [a]
-- take :: Int -> String -> String
on take(n, xs)
    set c to class of xs
    if list is c then
        if 0 < n then
            items 1 thru min(n, length of xs) of xs
        else
            {}
        end if
    else if string is c then
        if 0 < n then
            text 1 thru min(n, length of xs) of xs
        else
            ""
        end if
    else if script is c then
        set ys to {}
        repeat with i from 1 to n
            set v to |λ|() of xs
            if missing value is v then
                return ys
            else
                set end of ys to v
            end if
        end repeat
        return ys
    else
        missing value
    end if
end take


-- unlines :: [String] -> String
on unlines(xs)
    -- A single string formed by the intercalation
    -- of a list of strings with the newline character.
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, linefeed}
    set s to xs as text
    set my text item delimiters to dlm
    s
end unlines


-- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
on zipWith(f, xs, ys)
    set lng to min(length of xs, length of ys)
    set lst to {}
    if 1 > lng then
        return {}
    else
        tell mReturn(f)
            repeat with i from 1 to lng
                set end of lst to |λ|(item i of xs, item i of ys)
            end repeat
            return lst
        end tell
    end if
end zipWith

Output:

Price adjustments:

-0.05 -> Out of range.
 0.00 -> 0.10
 0.05 -> 0.10
 0.10 -> 0.18
 0.15 -> 0.26
 0.20 -> 0.32
 0.25 -> 0.38
 0.30 -> 0.44
 0.35 -> 0.50
 0.40 -> 0.54
 0.45 -> 0.58
 0.50 -> 0.62
 0.55 -> 0.66
 0.60 -> 0.70
 0.65 -> 0.74
 0.70 -> 0.78
 0.75 -> 0.82
 0.80 -> 0.86
 0.85 -> 0.90
 0.90 -> 0.94
 0.95 -> 0.98
 1.00 -> 1.00
 1.05 -> Out of range.

Arturo

pricePoints: [
    0.06 0.10       0.11 0.18       0.16 0.26       0.21 0.32
    0.26 0.38       0.31 0.44       0.36 0.50       0.41 0.54
    0.46 0.58       0.51 0.62       0.56 0.66       0.61 0.70
    0.66 0.74       0.71 0.78       0.76 0.82       0.81 0.86
    0.86 0.90       0.91 0.94       0.96 0.98       1.01 1.00
]

getPricePoint: function [price][
    loop pricePoints [limit,correct][
        if price < limit -> return correct
    ]
]

tests: [0.3793 0.4425 0.0746 0.6918 0.2993 0.5486 0.7849 0.9383 0.2292]

loop tests 'test [
    print [test "=>" getPricePoint test]
]

Output:

0.3793 => 0.54 
0.4425 => 0.58 
0.0746 => 0.18 
0.6918 => 0.78 
0.2993 => 0.44 
0.5486 => 0.66 
0.7849 => 0.86 
0.9383 => 0.98 
0.2292 => 0.38

AutoHotkey

; Submitted by MasterFocus --- http://tiny.cc/iTunis

Loop
{
  InputBox, OutputVar, Price Fraction Example, Insert the value to be rounded.`n* [ 0 < value < 1 ]`n* Press ESC or Cancel to exit, , 200, 150
  If ErrorLevel
    Break
  MsgBox % "Input: " OutputVar "`nResult: " PriceFraction( OutputVar )
}

;-----------------------------------------

PriceFraction( p_Input )
{

  If p_Input is not float ; returns 0 if input is not a float
    Return 0

  If ( ( p_Input <= 0 ) OR ( p_Input >= 1 ) ) ; returns 0 is input is out of range
    Return 0

  ; declaring the table (arbitrary delimiters in use are '§' and '|')
  l_List := "0.06|0.10§0.11|0.18§0.16|0.26§0.21|0.32§0.26|0.38§0.31|0.44§0.36|0.50§0.41|0.54§0.46|0.58§0.51|0.62§0.56|0.66§0.61|0.70§0.66|0.74§0.71|0.78§0.76|0.82§0.81|0.86§0.86|0.90§0.91|0.94§0.96|0.98§1.01|1.00"

  Loop, Parse, l_List, § ; retrieves each field (delimited by '§')
  {
    StringSplit, l_Array, A_LoopField, | ; splits current field (using delimiter '|')
    If ( p_Input <= l_Array1 )
      Return l_Array2 ; returns the second value if input <= first value
  }

  Return 0 ; returns 0, indicating failure (shouldn't be reached though)

}

AWK

BEGIN {
    O = ".06 .11 .16 .21 .26 .31 .36 .41 .46 .51 .56 .61 .66 .71 .76 .81 .86 .91 .96 1.01"
    N = ".10 .18 .26 .32 .38 .44 .50 .54 .58 .62 .66 .70 .74 .78 .82 .86 .90 .94 .98 1.00"
    fields = split(O,Oarr," ") # original values
    split(N,Narr," ") # replacement values
    for (i=-.01; i<=1.02; i+=.01) { # test
      printf("%5.2f = %4.2f\n",i,lookup(i))
    }
}
function lookup(n,  i) {
    if (n < 0 || n > 1.01) {
      return(0) # when input is out of range
    }
    for (i=1; i<=fields; i++) {
      # +10 is used because .11 returned .18 instead of .26
      # under AWK95, GAWK, and MAWK; Thompson Automation's TAWK worked correctly
      if (n+10 < Oarr[i]+10) {
        return(Narr[i])
      }
    }
}

BASIC

Works with: QBasic

This could also be done by building an array, but I felt that this was simpler.

DECLARE FUNCTION PriceFraction! (price AS SINGLE)

RANDOMIZE TIMER
DIM x AS SINGLE
x = RND
PRINT x, PriceFraction(x)

FUNCTION PriceFraction! (price AS SINGLE)
    'returns price unchanged if invalid value
    SELECT CASE price
        CASE IS < 0!
            PriceFraction! = price
        CASE IS < .06
            PriceFraction! = .1
        CASE IS < .11
            PriceFraction! = .18
        CASE IS < .16
            PriceFraction! = .26
        CASE IS < .21
            PriceFraction! = .32
        CASE IS < .26
            PriceFraction! = .38
        CASE IS < .31
            PriceFraction! = .44
        CASE IS < .36
            PriceFraction! = .5
        CASE IS < .41
            PriceFraction! = .54
        CASE IS < .46
            PriceFraction! = .58
        CASE IS < .51
            PriceFraction! = .62
        CASE IS < .56
            PriceFraction! = .66
        CASE IS < .61
            PriceFraction! = .7
        CASE IS < .66
            PriceFraction! = .74
        CASE IS < .71
            PriceFraction! = .78
        CASE IS < .76
            PriceFraction! = .82
        CASE IS < .81
            PriceFraction! = .86
        CASE IS < .86
            PriceFraction! = .9
        CASE IS < .91
            PriceFraction! = .94
        CASE IS < .96
            PriceFraction! = .98
        CASE IS < 1.01
            PriceFraction! = 1!
        CASE ELSE
            PriceFraction! = price
    END SELECT
END FUNCTION

Output:

(run 5 times)

.7388727      .82
.8593103      .9
.826687       .9
.3444635      .5
.0491907      .1

BASIC256

Translation of: Gambas

arraybase 1
dim byValue = {10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100}
dim byLimit = {6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96}

for byCount = 1 to 100
    for byCheck = 0 to byLimit[?]
	if byCount < byLimit[byCheck] then exit for
    next byCheck
    print ljust((byCount/100),4," "); " -> "; ljust((byValue[byCheck]/100),4," "); chr(9);
    if byCount mod 5 = 0 then print
next byCount
end

BBC BASIC

      PRINT FNpricefraction(0.5)
      END
      
      DEF FNpricefraction(p)
      IF p < 0.06 THEN = 0.10
      IF p < 0.11 THEN = 0.18
      IF p < 0.16 THEN = 0.26
      IF p < 0.21 THEN = 0.32
      IF p < 0.26 THEN = 0.38
      IF p < 0.31 THEN = 0.44
      IF p < 0.36 THEN = 0.50
      IF p < 0.41 THEN = 0.54
      IF p < 0.46 THEN = 0.58
      IF p < 0.51 THEN = 0.62
      IF p < 0.56 THEN = 0.66
      IF p < 0.61 THEN = 0.70
      IF p < 0.66 THEN = 0.74
      IF p < 0.71 THEN = 0.78
      IF p < 0.76 THEN = 0.82
      IF p < 0.81 THEN = 0.86
      IF p < 0.86 THEN = 0.90
      IF p < 0.91 THEN = 0.94
      IF p < 0.96 THEN = 0.98
      = 1.00

Commodore BASIC

We'll use a couple of arrays for translation. Should work for several other 8-bit BASICs after converting the screen control codes.

1 rem price fraction
2 rem rosetta code
10 data 0.06,0.1,0.11,0.18,0.16,0.26,0.21,0.32,0.26,0.38,0.31,0.44,0.36,0.5
20 data 0.41,0.54,0.46,0.58,0.51,0.62,0.56,0.66,0.61,0.70,0.66,0.74,0.71,0.78
30 data 0.76,0.82,0.81,0.86,0.86,0.90,0.91,0.94,0.96,0.98,1.01,1.0
35 rem up=user price, th=threshold,            pr=price, np=new price
40 dim th(20),pr(20):th(0)=0:pr(0)=0
45 for i=1 to 20:read th(i),pr(i):next
50 print chr$(147);chr$(14);"Price Fraction":print
60 print "What is the value to calculate (between 0.0 and 1.0)";:input up
65 if up<0 or up>1.0 then goto 60
70 gosub 500
80 print:print "You entered";up;chr$(157);", the new value is";np
90 print:print "Again (Y/N)? ";
95 get k$:if k$<>"y" and k$<>"n" then 95
100 print k$
110 if k$="y" then goto 50
115 end
500 for i=0 to 20
510 if up<th(i) then np=pr(i):return
520 next i
530 np=1:return

Output:

Price Fraction

What is the value to calculate (between 0.0 and 1.0)? 0.83344

You entered .83344, the new value is .9

Again (Y/N)? Y

Price Fraction

What is the value to calculate (between 0.0 and 1.0)? 0.05889

You entered .05889, the new value is .1

Again (Y/N)? Y

Price Fraction

What is the value to calculate (between 0.0 and 1.0)? 0.36

You entered .36, the new value is .54

Again (Y/N)? N
ready.

FreeBASIC

' FB 1.050.0 Win64

Function rescale(price As Double) As Double
  If price < 0.00 OrElse price > 1.00 Then Return price
  Select Case price
    Case Is < 0.06 : Return 0.10
    Case Is < 0.11 : Return 0.18
    Case Is < 0.16 : Return 0.26
    Case Is < 0.21 : Return 0.32
    Case Is < 0.26 : Return 0.38
    Case Is < 0.31 : Return 0.44
    Case Is < 0.36 : Return 0.50
    Case Is < 0.41 : Return 0.54
    Case Is < 0.46 : Return 0.58
    Case Is < 0.51 : Return 0.62
    Case Is < 0.56 : Return 0.66
    Case Is < 0.61 : Return 0.70
    Case Is < 0.66 : Return 0.74
    Case Is < 0.71 : Return 0.78
    Case Is < 0.76 : Return 0.82
    Case Is < 0.81 : Return 0.86
    Case Is < 0.86 : Return 0.90
    Case Is < 0.91 : Return 0.94
    Case Is < 0.96 : Return 0.98
  End Select
  Return 1.00
End Function

For i As Integer = 1 To 100
  Dim d As Double = i/100.0
  Print Using "#.##"; d;
  Print " -> ";
  Print Using "#.##"; rescale(d);
  Print "  ";
  If i Mod 5 = 0 Then Print
Next 

Print
Print "Press any key to quit"
Sleep

Output:

0.01 -> 0.10  0.02 -> 0.10  0.03 -> 0.10  0.04 -> 0.10  0.05 -> 0.10
0.06 -> 0.18  0.07 -> 0.18  0.08 -> 0.18  0.09 -> 0.18  0.10 -> 0.18
0.11 -> 0.26  0.12 -> 0.26  0.13 -> 0.26  0.14 -> 0.26  0.15 -> 0.26
0.16 -> 0.32  0.17 -> 0.32  0.18 -> 0.32  0.19 -> 0.32  0.20 -> 0.32
0.21 -> 0.38  0.22 -> 0.38  0.23 -> 0.38  0.24 -> 0.38  0.25 -> 0.38
0.26 -> 0.44  0.27 -> 0.44  0.28 -> 0.44  0.29 -> 0.44  0.30 -> 0.44
0.31 -> 0.50  0.32 -> 0.50  0.33 -> 0.50  0.34 -> 0.50  0.35 -> 0.50
0.36 -> 0.54  0.37 -> 0.54  0.38 -> 0.54  0.39 -> 0.54  0.40 -> 0.54
0.41 -> 0.58  0.42 -> 0.58  0.43 -> 0.58  0.44 -> 0.58  0.45 -> 0.58
0.46 -> 0.62  0.47 -> 0.62  0.48 -> 0.62  0.49 -> 0.62  0.50 -> 0.62
0.51 -> 0.66  0.52 -> 0.66  0.53 -> 0.66  0.54 -> 0.66  0.55 -> 0.66
0.56 -> 0.70  0.57 -> 0.70  0.58 -> 0.70  0.59 -> 0.70  0.60 -> 0.70
0.61 -> 0.74  0.62 -> 0.74  0.63 -> 0.74  0.64 -> 0.74  0.65 -> 0.74
0.66 -> 0.78  0.67 -> 0.78  0.68 -> 0.78  0.69 -> 0.78  0.70 -> 0.78
0.71 -> 0.82  0.72 -> 0.82  0.73 -> 0.82  0.74 -> 0.82  0.75 -> 0.82
0.76 -> 0.86  0.77 -> 0.86  0.78 -> 0.86  0.79 -> 0.86  0.80 -> 0.86
0.81 -> 0.90  0.82 -> 0.90  0.83 -> 0.90  0.84 -> 0.90  0.85 -> 0.90
0.86 -> 0.94  0.87 -> 0.94  0.88 -> 0.94  0.89 -> 0.94  0.90 -> 0.94
0.91 -> 0.98  0.92 -> 0.98  0.93 -> 0.98  0.94 -> 0.98  0.95 -> 0.98
0.96 -> 1.00  0.97 -> 1.00  0.98 -> 1.00  0.99 -> 1.00  1.00 -> 1.00

Gambas

Click this link to run this code

Public Sub Main()
Dim byValue As Byte[] = [10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100]
Dim byLimit As Byte[] = [6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96]
Dim byCount, byCheck As Byte

For byCount = 0 To 100
  For byCheck = 0 To byLimit.Max
    If byCount < byLimit[byCheck] Then Break
  Next
  Print Format(byCount / 100, "0.00") & " = " & Format(byValue[byCheck] / 100, "0.00") & gb.Tab;
  If byCount Mod 5 = 0 Then Print
Next

End

Output:

0.00 = 0.10
0.01 = 0.10     0.02 = 0.10     0.03 = 0.10     0.04 = 0.10     0.05 = 0.10
0.06 = 0.18     0.07 = 0.18     0.08 = 0.18     0.09 = 0.18     0.10 = 0.18
0.11 = 0.26     0.12 = 0.26     0.13 = 0.26     0.14 = 0.26     0.15 = 0.26
0.16 = 0.32     0.17 = 0.32     0.18 = 0.32     0.19 = 0.32     0.20 = 0.32
0.21 = 0.38     0.22 = 0.38     0.23 = 0.38     0.24 = 0.38     0.25 = 0.38
0.26 = 0.44     0.27 = 0.44     0.28 = 0.44     0.29 = 0.44     0.30 = 0.44
0.31 = 0.50     0.32 = 0.50     0.33 = 0.50     0.34 = 0.50     0.35 = 0.50
0.36 = 0.54     0.37 = 0.54     0.38 = 0.54     0.39 = 0.54     0.40 = 0.54
0.41 = 0.58     0.42 = 0.58     0.43 = 0.58     0.44 = 0.58     0.45 = 0.58
0.46 = 0.62     0.47 = 0.62     0.48 = 0.62     0.49 = 0.62     0.50 = 0.62
0.51 = 0.66     0.52 = 0.66     0.53 = 0.66     0.54 = 0.66     0.55 = 0.66
0.56 = 0.70     0.57 = 0.70     0.58 = 0.70     0.59 = 0.70     0.60 = 0.70
0.61 = 0.74     0.62 = 0.74     0.63 = 0.74     0.64 = 0.74     0.65 = 0.74
0.66 = 0.78     0.67 = 0.78     0.68 = 0.78     0.69 = 0.78     0.70 = 0.78
0.71 = 0.82     0.72 = 0.82     0.73 = 0.82     0.74 = 0.82     0.75 = 0.82
0.76 = 0.86     0.77 = 0.86     0.78 = 0.86     0.79 = 0.86     0.80 = 0.86
0.81 = 0.90     0.82 = 0.90     0.83 = 0.90     0.84 = 0.90     0.85 = 0.90
0.86 = 0.94     0.87 = 0.94     0.88 = 0.94     0.89 = 0.94     0.90 = 0.94
0.91 = 0.98     0.92 = 0.98     0.93 = 0.98     0.94 = 0.98     0.95 = 0.98
0.96 = 1.00     0.97 = 1.00     0.98 = 1.00     0.99 = 1.00     1.00 = 1.00

Liberty BASIC

dim DR(38)    'decimal range
dim PF(38)    'corresponding price fraction
range$="0.06 0.11 0.16 0.21 0.26 0.31 0.36 0.41 0.46 0.51 0.56 0.61 0.66 0.71 0.76 0.81 0.86 0.91 0.96 0.01"
frac$="0.10 0.18 0.26 0.32 0.38 0.44 0.50 0.54 0.58 0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90 0.94 0.98 1.00"
for i = 1 to 38
  DR(i)=val(word$(range$,i))
  PF(i)=val(word$(frac$,i))
next

for i = 0 to .99 step 0.03
  print i;" -> ";PriceFraction(i)
next
end

Function PriceFraction(n)
    PriceFraction=n  'return original if outside test bounds
    for i = 1 to 38
    if n<=DR(i) then
        PriceFraction=PF(i)
        exit for
    end if
    next
    end function

PureBasic

Procedure.f PriceFraction(price.f)
  ;returns price unchanged if value is invalid 
  Protected fraction
  Select price * 100
    Case 0 To 5
      fraction = 10
    Case 06 To 10
      fraction = 18
    Case 11 To 15
      fraction = 26
    Case 16 To 20
      fraction = 32
    Case 21 To 25
      fraction = 38
    Case 26 To 30
      fraction = 44
    Case 31 To 35
      fraction = 5
    Case 36 To 40
      fraction = 54
    Case 41 To 45
      fraction = 58
    Case 46 To 50
      fraction = 62
    Case 51 To 55
      fraction = 66
    Case 56 To 60
      fraction = 7
    Case 61 To 65
      fraction = 74
    Case 66 To 70
      fraction = 78
    Case 71 To 75
      fraction = 82
    Case 76 To 80
      fraction = 86
    Case 81 To 85
      fraction = 9
    Case 86 To 90
      fraction = 94
    Case 91 To 95
      fraction = 98
    Case 96 To 100
      fraction = 100
    Default
      ProcedureReturn price
  EndSelect
  
  ProcedureReturn fraction / 100
EndProcedure

If OpenConsole()
  Define x.f, i
  
  For i = 1 To 10
    x = Random(10000)/10000
    PrintN(StrF(x, 4) + " -> " + StrF(PriceFraction(x), 2))
  Next
  
  Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
  Input()
  CloseConsole()
EndIf

Output:

0.3793 -> 0.54
0.4425 -> 0.58
0.0746 -> 0.18
0.6918 -> 0.78
0.2993 -> 0.44
0.5486 -> 0.66
0.7848 -> 0.86
0.9383 -> 0.98
0.2292 -> 0.38
0.9560 -> 1.00

Run BASIC

data .06, .1,.11,.18,.16,.26,.21,.32,.26,.38,.31,.44,.36,.50,.41,.54,.46,.58,.51,.62
data .56,.66,.61,.70,.66,.74,.71,.78,.76,.82,.81,.86,.86,.90,.91,.94,.96,.98 

dim od(100)
dim nd(100)
for i = 1 to 19
read oldDec
read newDec
j = j + 1
for j = j to oldDec * 100
   nd(j) = newDec
next j
next i

[loop]
input "Gimme a number";numb
decm  = val(using("##",(numb mod 1) * 100))
print numb;" -->";nd(decm)

goto [loop]

Gimme a number?12.676
12.676 -->0.78
Gimme a number?4.876
4.876 -->0.94
Gimme a number?34.12
34.12 -->0.26

True BASIC

Translation of: BASIC

FUNCTION pricefraction(price)
    !returns price unchanged if invalid value
    SELECT CASE price
    CASE IS < 0
         LET pricefraction = price
    CASE IS < .06
         LET pricefraction = .1
    CASE IS < .11
         LET pricefraction = .18
    CASE IS < .16
         LET pricefraction = .26
    CASE IS < .21
         LET pricefraction = .32
    CASE IS < .26
         LET pricefraction = .38
    CASE IS < .31
         LET pricefraction = .44
    CASE IS < .36
         LET pricefraction = .5
    CASE IS < .41
         LET pricefraction = .54
    CASE IS < .46
         LET pricefraction = .58
    CASE IS < .51
         LET pricefraction = .62
    CASE IS < .56
         LET pricefraction = .66
    CASE IS < .61
         LET pricefraction = .7
    CASE IS < .66
         LET pricefraction = .74
    CASE IS < .71
         LET pricefraction = .78
    CASE IS < .76
         LET pricefraction = .82
    CASE IS < .81
         LET pricefraction = .86
    CASE IS < .86
         LET pricefraction = .9
    CASE IS < .91
         LET pricefraction = .94
    CASE IS < .96
         LET pricefraction = .98
    CASE IS < 1.01
         LET pricefraction = 1
    CASE ELSE
         LET pricefraction = price
    END SELECT
END FUNCTION

RANDOMIZE
FOR i = 1 TO 100
    LET d = RND
    PRINT USING "#.##": d;
    PRINT " -> ";
    PRINT USING "#.##  ": pricefraction(d);
    IF REMAINDER(i,5) = 0 THEN PRINT
NEXT i
END

uBasic/4tH

Translation of: Forth

Works with: R3

For i = 0 To 100 Step 5
  Print Using "+?.##"; i, Using "+?.##"; FUNC(_Normalize (FUNC(_Classify (i))))
Next 

End

_Normalize                             ' normalize the price
  Param (1)                            ' class
  Local (4)                            ' accumulator, increment, switch and iterator
  
  b@ = 0 : c@ = 10 : d@ = 2            ' setup accumulator, increment and switch
  
  For e@ = 0 to a@                     ' from zero to class
    If And(e@ + 1, d@) Then d@ = And(d@ + d@, 15) : c@ = c@ - 2
    b@ = b@ + c@                       ' switch increment if needed
  Next                                 ' accumulate price
Return (Min(b@, 100))                  ' clip top of price in accumulator
                                       ' calculate class
_Classify Param (1) : Return ((a@ - (a@>0)) / 5)

Output:

0.00    0.10
0.05    0.10
0.10    0.18
0.15    0.26
0.20    0.32
0.25    0.38
0.30    0.44
0.35    0.50
0.40    0.54
0.45    0.58
0.50    0.62
0.55    0.66
0.60    0.70
0.65    0.74
0.70    0.78
0.75    0.82
0.80    0.86
0.85    0.90
0.90    0.94
0.95    0.98
1.00    1.00

0 OK, 0:115

VBA

Option Explicit

Sub Main()
Dim test, i As Long
    test = Array(0.34, 0.070145, 0.06, 0.05, 0.50214, 0.56, 1#, 0.99, 0#, 0.7388727)
    For i = 0 To UBound(test)
        Debug.Print test(i) & " := " & Price_Fraction(CSng(test(i)))
    Next i
End Sub

Private Function Price_Fraction(n As Single) As Single
Dim Vin, Vout, i As Long
    Vin = Array(0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01)
    Vout = Array(0.1, 0.18, 0.26, 0.32, 0.38, 0.44, 0.5, 0.54, 0.58, 0.62, 0.66, 0.7, 0.74, 0.78, 0.82, 0.86, 0.9, 0.94, 0.98, 1#)
    For i = 0 To UBound(Vin)
        If n < Vin(i) Then Price_Fraction = Vout(i): Exit For
    Next i
End Function

Output:

0.34 := 0.5
0.070145 := 0.18
0.06 := 0.18
0.05 := 0.1
0.50214 := 0.62
0.56 := 0.7
1 := 1
0.99 := 1
0 := 0.1
0.7388727 := 0.82

Yabasic

Translation of: BASIC256

data 10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100
data 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96

dim od(21)
for i = 1 to 20
    read oldDec
    od(i) = oldDec
next i
dim nd(20)
for j = 1 to 19
	read newDec
    nd(j) = newDec
next j

for i = 1 to 100
    for j = 1 to arraysize(nd(),1)-1
		if i < nd(j)  break
	next j
	print (i/100) using ("#.##"), " -> ", (od(j)/100) using ("#.##"), "\t";
	if mod(i, 5) = 0  print
next i
end

Beads

beads 1 program 'Price fraction'

record a_table
	value
	rescaled
	
const table : array of a_table = [<
	value, rescaled
	0.06,  0.10
	0.11,  0.18
	0.16,  0.26
	0.21,  0.32
	0.26,  0.38
	0.31,  0.44
	0.36,  0.50
	0.41,  0.54
	0.46,  0.58
	0.51,  0.62
	0.56,  0.66
	0.61,  0.70
	0.66,  0.74
	0.71,  0.78
	0.76,  0.82
	0.81,  0.86
	0.86,  0.90
	0.91,  0.94
	0.96,  0.98
	1.01,  1.00 >]

const a_test = [0.05 0.62 0.34 0.93 0.45]

calc main_init
	loop across:a_test val:v
		loop across:table index:ix
			if v < table[ix].value
				log "{v} => {table[ix].rescaled}"
				exit

Output:

0.05 => 0.1
0.62 => 0.74
0.34 => 0.5
0.93 => 0.98
0.45 => 0.58

Bracmat

This solution applies a string comparison.

( ( convert
  =   
    .         ("0.06"."0.10")
              ("0.11"."0.18")
              ("0.16"."0.26")
              ("0.21"."0.32")
              ("0.26"."0.38")
              ("0.31"."0.44")
              ("0.36"."0.50")
              ("0.41"."0.54")
              ("0.46"."0.58")
              ("0.51"."0.62")
              ("0.56"."0.66")
              ("0.61"."0.70")
              ("0.66"."0.74")
              ("0.71"."0.78")
              ("0.76"."0.82")
              ("0.81"."0.86")
              ("0.86"."0.90")
              ("0.91"."0.94")
              ("0.96"."0.98")
              ("1.01"."1.00")
          : ? (>!arg.?arg) ?
        & !arg
      | "invalid input"
  )
& -1:?n
&   whl
  ' ( !n+1:?n:<103
    & ( @(!n:? [<2)&str$("0.0" !n):?a
      | @(!n:? [<3)&str$("0." !n):?a
      |   @(!n:?ones [-3 ?decimals)
        & str$(!ones "." !decimals):?a
      )
    & out$(!a "-->" convert$!a)
    )
)

Output:

0.00 --> 0.10
0.01 --> 0.10
0.02 --> 0.10
0.03 --> 0.10
0.04 --> 0.10
0.05 --> 0.10
0.06 --> 0.18
0.07 --> 0.18
0.08 --> 0.18
0.09 --> 0.18
0.10 --> 0.18
0.11 --> 0.26
0.12 --> 0.26
0.13 --> 0.26
0.14 --> 0.26
0.15 --> 0.26
0.16 --> 0.32
0.17 --> 0.32
  ...
0.85 --> 0.90
0.86 --> 0.94
0.87 --> 0.94
0.88 --> 0.94
0.89 --> 0.94
0.90 --> 0.94
0.91 --> 0.98
0.92 --> 0.98
0.93 --> 0.98
0.94 --> 0.98
0.95 --> 0.98
0.96 --> 1.00
0.97 --> 1.00
0.98 --> 1.00
0.99 --> 1.00
1.00 --> 1.00
1.01 --> invalid input
1.02 --> invalid input

C

#include<stdio.h>

double table[][2] = {
	{0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32},
	{0.26, 0.38}, {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54},
	{0.46, 0.58}, {0.51, 0.62}, {0.56, 0.66}, {0.61, 0.70},
	{0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, {0.81, 0.86},
	{0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00},
	{-1, 0}, /* guarding element */
};

double price_fix(double x)
{
	int i;
	for (i = 0; table[i][0] > 0; i++)
		if (x < table[i][0]) return table[i][1];

	abort(); /* what else to do? */
}

int main()
{
	int i;
	for (i = 0; i <= 100; i++)
		printf("%.2f %.2f\n", i / 100., price_fix(i / 100.));

	return 0;
}

C#

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            for (int x = 0; x < 10; x++)
            {
                Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", ((double)x) / 10, SpecialRound(((double)x) / 10));
            }

            Console.WriteLine();

            for (int x = 0; x < 10; x++)
            {
                Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", ((double)x) / 10 + 0.05, SpecialRound(((double)x) / 10 + 0.05));
            }

            Console.WriteLine();
            Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", 1.01, SpecialRound(1.01));

            Console.Read();
        }

        private static double SpecialRound(double inValue)
        {
            if (inValue > 1) return 1;

            double[] Splitters = new double[] { 
                   0.00 , 0.06 , 0.11 , 0.16 , 0.21 , 
                   0.26 , 0.31 , 0.36 , 0.41 , 0.46 , 
                   0.51 , 0.56 , 0.61 , 0.66 , 0.71 , 
                   0.76 , 0.81 , 0.86 , 0.91 , 0.96 };

            double[] replacements = new double[] { 
                    0.10 , 0.18 , 0.26 , 0.32 , 0.38 ,
                    0.44 , 0.50 , 0.54 , 0.58 , 0.62 , 
                    0.66 , 0.70 , 0.74 , 0.78 , 0.82 , 
                    0.86 , 0.90 , 0.94 , 0.98 , 1.00 };

            for (int x = 0; x < Splitters.Length - 1; x++)
            {
                if (inValue >= Splitters[x] &&
                    inValue < Splitters[x + 1])
                {
                    return replacements[x];
                }
            }

            return inValue;
        }
    }
}

C++

#include <iostream>
#include <cmath>

int main( ) {
   double froms[ ] = { 0.00 , 0.06 , 0.11 , 0.16 , 0.21 , 0.26 , 
       0.31 , 0.36 , 0.41 , 0.46 , 0.51 , 0.56 , 0.61 , 0.66 ,
       0.71 , 0.76 , 0.81 , 0.86 , 0.91 , 0.96 } ;
   double tos[ ] = { 0.06 , 0.11 , 0.16 , 0.21 , 0.26 , 0.31 ,
      0.36 , 0.41 , 0.46 , 0.51 , 0.56 , 0.61 , 0.66 , 0.71 ,
      0.76 , 0.81 , 0.86 , 0.91 , 0.96 , 1.01 } ;
   double replacements [] = { 0.10 , 0.18 , 0.26 , 0.32 , 0.38 ,
      0.44 , 0.50 , 0.54 , 0.58 , 0.62 , 0.66 , 0.70 , 0.74 ,
      0.78 , 0.82 , 0.86 , 0.90 , 0.94 , 0.98 , 1.00 } ;
   double number = 0.1 ;
   std::cout << "Enter a fractional number between 0 and 1 ( 0 to end )!\n" ;
   std::cin >> number ;
   while ( number != 0 ) {
      if ( number < 0 || number > 1 ) {
	 std::cerr << "Error! Only positive values between 0 and 1 are allowed!\n" ;
	 return 1 ;
      }
      int n = 0 ;
      while ( ! ( number >= froms[ n ] && number < tos[ n ] ) ) 
	 n++ ;
      std::cout << "-->" << replacements[ n ] << '\n' ;
      std::cout << "Enter a fractional number ( 0 to end )!\n" ;
      std::cin >> number ;
   }
   return 0 ;
}

Output:

Enter a fractional number between 0 and 1 ( 0 to end )!
0.7
-->0.78
Enter a fractional number ( 0 to end )!
0.32
-->0.5
Enter a fractional number ( 0 to end )!
0.12
-->0.26
Enter a fractional number ( 0 to end )!
0

Clipper

FUNCTION PriceFraction( npQuantDispensed )
    LOCAL aPriceFraction := { {0,.06,.1},;
                            {.06,.11,.18}, ;
                            {.11,.16,.26}, ;
                            {.16,.21,.32}, ;
                            {.21,.26,.38}, ;
                            {.26,.31,.44}, ;
                            {.31,.36,.5}, ;
                            {.36,.41,.54}, ;
                            {.41,.46,.58}, ;
                            {.46,.51,.62}, ;
                            {.51,.56,.66}, ;
                            {.56,.61,.7}, ;
                            {.61,.66,.74}, ;
                            {.66,.71,.78}, ;
                            {.71,.76,.82}, ;
                            {.76,.81,.86}, ;
                            {.81,.86,.9}, ;
                            {.86,.91,.94}, ;
                            {.91,.96,.98} }
    LOCAL nResult
    LOCAL nScan
    IF npQuantDispensed = 0
            nResult = 0
    ELSEIF npQuantDispensed >= .96
            nResult = 1
    ELSE
            nScan := ASCAN( aPriceFraction, ;
                   { |aItem| npQuantDispensed >= aItem[ 1 ] .AND.;
                             npQuantDispensed <  aItem[ 2 ] } )
            nResult := aPriceFraction[ nScan ][ 3 ]
    END IF
    RETURN nResult

The function above crashes with an array access bound error if the value passed is negative. Also, the spec. indicates that 0.00 should be replaced with standard value 0.10, not 0. The following is a more concise solution:

Procedure Main()
   Local i
   For i := -0.02 to 1.02 STEP 0.03
      ? i, "->", PriceFraction(i), i+0.02, "->", PriceFraction(i+0.02)
   Next
Return


Static Function PriceFraction( nValue )
   Local nResult
   Local n
   // Function is only defined for values 0 to 1.00
   // Return NIL for anything else
   // Table of values {V1, V2} = {Threshhold, Standard value}
   #define TV_THRESHHOLD 1
   #define TV_STD_VALUE  2
   Local aTable := { {0,    NIL },;
                     {0.06, 0.10},;
                     {0.11, 0.18},;
                     {0.16, 0.26},;
                     {0.21, 0.32},;
                     {0.26, 0.38},;
                     {0.31, 0.44},;
                     {0.36, 0.50},;
                     {0.41, 0.54},;
                     {0.46, 0.58},;
                     {0.51, 0.62},;
                     {0.56, 0.66},;
                     {0.61, 0.70},;
                     {0.66, 0.74},;
                     {0.71, 0.78},;
                     {0.76, 0.82},;
                     {0.81, 0.86},;
                     {0.86, 0.90},;
                     {0.91, 0.94},;
                     {0.96, 0.98},;
                     {1.01, 1.00} }
   n := AScan( aTable, {|x| nValue < x[TV_THRESHHOLD] })
   If n > 0
      nResult := aTable[n][TV_STD_VALUE]
   Else
      nResult := NIL
   Endif
Return nResult

Output:

        -0.02 -> NIL          0.00 ->          0.10
         0.01 ->          0.10          0.03 ->          0.10
         0.04 ->          0.10          0.06 ->          0.18
         0.07 ->          0.18          0.09 ->          0.18
         0.10 ->          0.18          0.12 ->          0.26
         0.13 ->          0.26          0.15 ->          0.26
         0.16 ->          0.32          0.18 ->          0.32
         0.19 ->          0.32          0.21 ->          0.38
         0.22 ->          0.38          0.24 ->          0.38
         0.25 ->          0.38          0.27 ->          0.44
         0.28 ->          0.44          0.30 ->          0.44
         0.31 ->          0.50          0.33 ->          0.50
         0.34 ->          0.50          0.36 ->          0.54
         0.37 ->          0.54          0.39 ->          0.54
         0.40 ->          0.54          0.42 ->          0.58
         0.43 ->          0.58          0.45 ->          0.58
         0.46 ->          0.62          0.48 ->          0.62
         0.49 ->          0.62          0.51 ->          0.66
         0.52 ->          0.66          0.54 ->          0.66
         0.55 ->          0.66          0.57 ->          0.70
         0.58 ->          0.70          0.60 ->          0.70
         0.61 ->          0.74          0.63 ->          0.74
         0.64 ->          0.74          0.66 ->          0.78
         0.67 ->          0.78          0.69 ->          0.78
         0.70 ->          0.78          0.72 ->          0.82
         0.73 ->          0.82          0.75 ->          0.82
         0.76 ->          0.86          0.78 ->          0.86
         0.79 ->          0.86          0.81 ->          0.90
         0.82 ->          0.90          0.84 ->          0.90
         0.85 ->          0.90          0.87 ->          0.94
         0.88 ->          0.94          0.90 ->          0.94
         0.91 ->          0.98          0.93 ->          0.98
         0.94 ->          0.98          0.96 ->          1.00
         0.97 ->          1.00          0.99 ->          1.00
         1.00 ->          1.00          1.02 -> NIL

Clojure

Translation of: JavaScript

(def values [10 18 26 32 38 44 50 54 58 62 66 70 74 78 82 86 90 94 98 100])

(defn price [v] 
  (format "%.2f" (double (/ (values (int (/ (- (* v 100) 1) 5))) 100))))

Output:

user=> (price 0.50)
"0.62"
user=> (let [k (map #(double (/ % 100)) (range 101))] (sort (zipmap k (map #(price %) k))))
([0.0 "0.10"] [0.01 "0.10"] [0.02 "0.10"] [0.03 "0.10"] [0.04 "0.10"] [0.05 "0.10"]
 [0.06 "0.18"] [0.07 "0.18"] [0.08 "0.18"] [0.09 "0.18"] [0.1 "0.18"] 
 [0.11 "0.26"] [0.12 "0.26"] [0.13 "0.26"] [0.14 "0.26"] [0.15 "0.26"] 
 [0.16 "0.32"] [0.17 "0.32"] [0.18 "0.32"] [0.19 "0.32"] [0.2 "0.32"] 
 [0.21 "0.38"] [0.22 "0.38"] [0.23 "0.38"] [0.24 "0.38"] [0.25 "0.38"]
 [0.26 "0.44"] [0.27 "0.44"] [0.28 "0.44"] [0.29 "0.44"] [0.3 "0.44"]
 [0.31 "0.50"] [0.32 "0.50"] [0.33 "0.50"] [0.34 "0.50"] [0.35 "0.50"] 
 [0.36 "0.54"] [0.37 "0.54"] [0.38 "0.54"] [0.39 "0.54"] [0.4 "0.54"] 
 [0.41 "0.58"] [0.42 "0.58"] [0.43 "0.58"] [0.44 "0.58"] [0.45 "0.58"] 
 [0.46 "0.62"] [0.47 "0.62"] [0.48 "0.62"] [0.49 "0.62"] [0.5 "0.62"] 
 [0.51 "0.66"] [0.52 "0.66"] [0.53 "0.66"] [0.54 "0.66"] [0.55 "0.66"] 
 [0.56 "0.70"] [0.57 "0.70"] [0.58 "0.70"] [0.59 "0.70"] [0.6 "0.70"] 
 [0.61 "0.74"] [0.62 "0.74"] [0.63 "0.74"] [0.64 "0.74"] [0.65 "0.74"] 
 [0.66 "0.78"] [0.67 "0.78"] [0.68 "0.78"] [0.69 "0.78"] [0.7 "0.78"] 
 [0.71 "0.82"] [0.72 "0.82"] [0.73 "0.82"] [0.74 "0.82"] [0.75 "0.82"] 
 [0.76 "0.86"] [0.77 "0.86"] [0.78 "0.86"] [0.79 "0.86"] [0.8 "0.86"] 
 [0.81 "0.90"] [0.82 "0.90"] [0.83 "0.90"] [0.84 "0.90"] [0.85 "0.90"] 
 [0.86 "0.94"] [0.87 "0.94"] [0.88 "0.94"] [0.89 "0.94"] [0.9 "0.94"] 
 [0.91 "0.98"] [0.92 "0.98"] [0.93 "0.98"] [0.94 "0.98"] [0.95 "0.98"] 
 [0.96 "1.00"] [0.97 "1.00"] [0.98 "1.00"] [0.99 "1.00"] [1.0 "1.00"])

Common Lisp

(defun scale (value)
  (cond ((minusp value) (error "invalid value: ~A" value))
        ((< value 0.06) 0.10)
        ((< value 0.11) 0.18)
        ((< value 0.16) 0.26)
        ((< value 0.21) 0.32)
        ((< value 0.26) 0.38)
        ((< value 0.31) 0.44)
        ((< value 0.36) 0.50)
        ((< value 0.41) 0.54)
        ((< value 0.46) 0.58)
        ((< value 0.51) 0.62)
        ((< value 0.56) 0.66)
        ((< value 0.61) 0.70)
        ((< value 0.66) 0.74)
        ((< value 0.71) 0.78)
        ((< value 0.76) 0.82)
        ((< value 0.81) 0.86)
        ((< value 0.86) 0.90)
        ((< value 0.91) 0.94)
        ((< value 0.96) 0.98)
        ((< value 1.01) 1.00)
        (t (error "invalid value: ~A" value))))

D

import std.stdio, std.range;

double priceRounder(in double price) pure nothrow
in {
    assert(price >= 0 && price <= 1.0);
} body {
    static immutable cin  = [.06, .11, .16, .21, .26, .31, .36, .41,
                             .46, .51, .56, .61, .66, .71, .76, .81,
                             .86, .91, .96, 1.01],
                     cout = [.10, .18, .26, .32, .38, .44, .50, .54,
                             .58, .62, .66, .70, .74, .78, .82, .86,
                             .90, .94, .98, 1.00];
    return cout[cin.assumeSorted.lowerBound(price).length];
}

void main() {
    foreach (const price; [0.7388727, 0.8593103, 0.826687, 0.3444635])
        price.priceRounder.writeln;
}

Output:

0.82
0.9
0.9
0.5

Dart

Translation of: Swift

class Range {
  final double start;
  final double end;

  Range(this.start, this.end);

  bool contains(double value) {
    return value >= start && value < end;
  }
}

List<MapEntry<Range, double>> ranges = [
  MapEntry(Range(0.00, 0.06), 0.10),
  MapEntry(Range(0.06, 0.11), 0.18),
  MapEntry(Range(0.11, 0.16), 0.26),
  MapEntry(Range(0.16, 0.21), 0.32),
  MapEntry(Range(0.21, 0.26), 0.38),
  MapEntry(Range(0.26, 0.31), 0.44),
  MapEntry(Range(0.31, 0.36), 0.50),
  MapEntry(Range(0.36, 0.41), 0.54),
  MapEntry(Range(0.41, 0.46), 0.58),
  MapEntry(Range(0.46, 0.51), 0.62),
  MapEntry(Range(0.51, 0.56), 0.66),
  MapEntry(Range(0.56, 0.61), 0.70),
  MapEntry(Range(0.61, 0.66), 0.74),
  MapEntry(Range(0.66, 0.71), 0.78),
  MapEntry(Range(0.71, 0.76), 0.82),
  MapEntry(Range(0.76, 0.81), 0.86),
  MapEntry(Range(0.81, 0.86), 0.90),
  MapEntry(Range(0.86, 0.91), 0.94),
  MapEntry(Range(0.91, 0.96), 0.98),
  MapEntry(Range(0.96, 1.01), 1.00),
];

double adjustDouble(double val, List<MapEntry<Range, double>> ranges) {
  for (var range in ranges) {
    if (range.key.contains(val)) {
      return range.value;
    }
  }
  return val; // Return the original value if no range is found
}

void main() {
  for (double val = 0.0; val <= 1.0; val += 0.01) {
    String strFmt(double n) => n.toStringAsFixed(2);

    double adjusted = adjustDouble(val, ranges);
    print("${strFmt(val)} -> ${strFmt(adjusted)}");
  }
}

Output:

0.00 -> 0.10
0.01 -> 0.10
0.02 -> 0.10
0.03 -> 0.10
0.04 -> 0.10
0.05 -> 0.10
0.06 -> 0.18
0.07 -> 0.18
0.08 -> 0.18
0.09 -> 0.18
0.10 -> 0.18
0.11 -> 0.18
0.12 -> 0.26
0.13 -> 0.26
0.14 -> 0.26
0.15 -> 0.26
0.16 -> 0.32
0.17 -> 0.32
0.18 -> 0.32
0.19 -> 0.32
0.20 -> 0.32
0.21 -> 0.38
0.22 -> 0.38
0.23 -> 0.38
0.24 -> 0.38
0.25 -> 0.38
0.26 -> 0.44
0.27 -> 0.44
0.28 -> 0.44
0.29 -> 0.44
0.30 -> 0.44
0.31 -> 0.50
0.32 -> 0.50
0.33 -> 0.50
0.34 -> 0.50
0.35 -> 0.50
0.36 -> 0.54
0.37 -> 0.54
0.38 -> 0.54
0.39 -> 0.54
0.40 -> 0.54
0.41 -> 0.58
0.42 -> 0.58
0.43 -> 0.58
0.44 -> 0.58
0.45 -> 0.58
0.46 -> 0.62
0.47 -> 0.62
0.48 -> 0.62
0.49 -> 0.62
0.50 -> 0.62
0.51 -> 0.66
0.52 -> 0.66
0.53 -> 0.66
0.54 -> 0.66
0.55 -> 0.66
0.56 -> 0.70
0.57 -> 0.70
0.58 -> 0.70
0.59 -> 0.70
0.60 -> 0.70
0.61 -> 0.74
0.62 -> 0.74
0.63 -> 0.74
0.64 -> 0.74
0.65 -> 0.74
0.66 -> 0.78
0.67 -> 0.78
0.68 -> 0.78
0.69 -> 0.78
0.70 -> 0.78
0.71 -> 0.82
0.72 -> 0.82
0.73 -> 0.82
0.74 -> 0.82
0.75 -> 0.82
0.76 -> 0.86
0.77 -> 0.86
0.78 -> 0.86
0.79 -> 0.86
0.80 -> 0.86
0.81 -> 0.90
0.82 -> 0.90
0.83 -> 0.90
0.84 -> 0.90
0.85 -> 0.90
0.86 -> 0.94
0.87 -> 0.94
0.88 -> 0.94
0.89 -> 0.94
0.90 -> 0.94
0.91 -> 0.98
0.92 -> 0.98
0.93 -> 0.98
0.94 -> 0.98
0.95 -> 0.98
0.96 -> 1.00
0.97 -> 1.00
0.98 -> 1.00
0.99 -> 1.00

Delphi

See Pascal.

EasyLang

n[] = [ 10 18 26 32 38 44 50 54 58 62 66 70 74 78 82 86 90 94 98 100 ]
func conv p .
   cat = (p - 1) div 5 + 1
   return n[cat]
.
for in = 5 step 5 to 100
   if in = 100
      in$ = "1.00"
   elif in < 10
      in$ = "0.0" & in
   else
      in$ = "0." & in
   .
   out = conv in
   if out = 100
      out$ = "1.00"
   else
      out$ = "0." & out
   .
   print in$ & " -> " & out$
.

Output:

0.05 -> 0.10
0.10 -> 0.18
0.15 -> 0.26
0.20 -> 0.32
0.25 -> 0.38
0.30 -> 0.44
0.35 -> 0.50
0.40 -> 0.54
0.45 -> 0.58
0.50 -> 0.62
0.55 -> 0.66
0.60 -> 0.70
0.65 -> 0.74
0.70 -> 0.78
0.75 -> 0.82
0.80 -> 0.86
0.85 -> 0.90
0.90 -> 0.94
0.95 -> 0.98
1.00 -> 1.00

Eiffel

class
	APPLICATION

create
	make

feature

	make
			--Tests the price_adjusted feature.
		local
			i: REAL
		do
			create price_fraction.initialize
			from
				i := 5
			until
				i = 100
			loop
				io.put_string ("Given: ")
				io.put_real (i / 100)
				io.put_string ("%TAdjusted:")
				io.put_real (price_fraction.adjusted_price (i / 100))
				io.new_line
				i := i + 5
			end
		end

	price_fraction: PRICE_FRACTION

end

class
	PRICE_FRACTION

create
	initialize

feature

	initialize
			-- Initializes limit and price to the given values.
		do
			limit := <<0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01>>
			price := <<0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.81, 0.86, 0.90, 0.94, 0.98, 1.00>>
		end

	adjusted_price (n: REAL): REAL
			-- Adjusted price according to the given price values.
		local
			i: INTEGER
			found: BOOLEAN
		do
			from
				i := 1
			until
				i > limit.count or found
			loop
				if n <= limit [i] then
					Result := (price [i])
					found := True
				end
				i := i + 1
			end
		end

feature {NONE}

	limit: ARRAY [REAL]

	price: ARRAY [REAL]

end

Output:

Given: 0.05    Adjusted:0.1
Given: 0.1     Adjusted:0.18
Given: 0.15    Adjusted:0.26
Given: 0.2     Adjusted:0.32
Given: 0.25    Adjusted:0.38
Given: 0.3     Adjusted:0.44
Given: 0.35    Adjusted:0.5
Given: 0.4     Adjusted:0.54
Given: 0.45    Adjusted:0.58
Given: 0.5     Adjusted:0.62
Given: 0.55    Adjusted:0.66
Given: 0.6     Adjusted:0.7
Given: 0.65    Adjusted:0.74
Given: 0.7     Adjusted:0.78
Given: 0.75    Adjusted:0.81
Given: 0.8     Adjusted:0.86
Given: 0.85    Adjusted:0.9
Given: 0.9     Adjusted:0.94
Given: 0.95    Adjusted:0.98

Elixir

defmodule Price do
  @table [ {0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38},
           {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62},
           {0.56, 0.66}, {0.61, 0.70}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82},
           {0.81, 0.86}, {0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00} ]
  
  def fraction(value) when value in 0..1 do
    {_, standard_value} = Enum.find(@table, fn {upper_limit, _} -> value < upper_limit end)
    standard_value
  end
end

val = for i <- 0..100, do: i/100
Enum.each(val, fn x ->
  :io.format "~5.2f ->~5.2f~n", [x, Price.fraction(x)]
end)

Output:

 0.00 -> 0.10
 0.01 -> 0.10
 0.02 -> 0.10
 0.03 -> 0.10
 0.04 -> 0.10
 0.05 -> 0.10
 0.06 -> 0.18
 0.07 -> 0.18
 0.08 -> 0.18
 0.09 -> 0.18
 0.10 -> 0.18
 0.11 -> 0.26
...
 0.95 -> 0.98
 0.96 -> 1.00
 0.97 -> 1.00
 0.98 -> 1.00
 0.99 -> 1.00
 1.00 -> 1.00

Erlang

priceFraction(N) when N < 0 orelse N > 1 ->
    erlang:error('Values must be between 0 and 1.');
priceFraction(N) when N < 0.06 -> 0.10;
priceFraction(N) when N < 0.11 -> 0.18;
priceFraction(N) when N < 0.16 -> 0.26;
priceFraction(N) when N < 0.21 -> 0.32;
priceFraction(N) when N < 0.26 -> 0.38;
priceFraction(N) when N < 0.31 -> 0.44;
priceFraction(N) when N < 0.36 -> 0.50;
priceFraction(N) when N < 0.41 -> 0.54;
priceFraction(N) when N < 0.46 -> 0.58;
priceFraction(N) when N < 0.51 -> 0.62;
priceFraction(N) when N < 0.56 -> 0.66;
priceFraction(N) when N < 0.61 -> 0.70;
priceFraction(N) when N < 0.66 -> 0.74;
priceFraction(N) when N < 0.71 -> 0.78;
priceFraction(N) when N < 0.76 -> 0.82;
priceFraction(N) when N < 0.81 -> 0.86;
priceFraction(N) when N < 0.86 -> 0.90;
priceFraction(N) when N < 0.91 -> 0.94;
priceFraction(N) when N < 0.96 -> 0.98;
priceFraction(N) -> 1.00.

Euphoria

Translation of: C

constant table = {
    {0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32},
    {0.26, 0.38}, {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54},
    {0.46, 0.58}, {0.51, 0.62}, {0.56, 0.66}, {0.61, 0.70},
    {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, {0.81, 0.86},
    {0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00}
}

function price_fix(atom x)
    for i = 1 to length(table) do
        if x < table[i][1] then
            return table[i][2]
        end if
    end for
    return -1
end function

for i = 0 to 99 do
    printf(1, "%.2f %.2f\n", { i/100, price_fix(i/100) })
end for

F#

Inspired by Python's bisect solution. Using decimal (System.Decimal) to avoid number representation problems with floats.

let cin = [ 0.06m .. 0.05m ..1.01m ]
let cout = [0.1m; 0.18m] @ [0.26m .. 0.06m .. 0.44m] @ [0.50m .. 0.04m .. 0.98m] @ [1.m]

let priceadjuster p =
    let rec bisect lo hi = 
        if lo < hi then
            let mid = (lo+hi)/2.
            let left = p < cin.[int mid]
            bisect (if left then lo else mid+1.) (if left then mid else hi)
        else lo    

    if p < 0.m || 1.m < p then p
    else cout.[int (bisect 0. (float cin.Length))]

[ 0.m .. 0.01m .. 1.m ]
|> Seq.ofList
|> Seq.iter (fun p -> printfn "%.2f -> %.2f" p (priceadjuster p))

Output:

The same as shown by Ada as of 2013-11-03T17:42Z (apart from whitespace formatting)

Factor

CONSTANT: dispensary-data {
{ 0.06 0.10 }
{ 0.11 0.18 }
{ 0.16 0.26 }
{ 0.21 0.32 }
{ 0.26 0.38 }
{ 0.31 0.44 }
{ 0.36 0.50 }
{ 0.41 0.54 }
{ 0.46 0.58 }
{ 0.51 0.62 }
{ 0.56 0.66 }
{ 0.61 0.70 }
{ 0.66 0.74 }
{ 0.71 0.78 }
{ 0.76 0.82 }
{ 0.81 0.86 }
{ 0.86 0.90 }
{ 0.91 0.94 }
{ 0.96 0.98 }
{ 1.01 1.00 } }

: price-fraction ( n -- n ) dispensary-data [ first over >= ] find 2nip second ;

{ 0 0.5 0.65 0.66 1 } [ price-fraction ] map

Output:

{ 0.1 0.62 0.74 0.74 1.0 }

Fantom

class Defn // to hold the three numbers from a 'row' in the table
{
  Float low
  Float high
  Float value
  new make (Float low, Float high, Float value)
  {
    this.low = low
    this.high = high
    this.value = value
  }
}

class PriceConverter
{
  Defn[] defns := [,]
  new make (Str table) // process given table and store numbers from each row in a defn
  {
    table.split('\n').each |Str line|
    {
      data := line.split
      defns.add (Defn(Float.fromStr(data[1]), Float.fromStr(data[3]), Float.fromStr(data[5])))
    }
  }

  public Float convert (Float price) // convert by looking through list of defns
  {
    Float result := price
    defns.each |Defn defn|
    {
      if (price >= defn.low && price < defn.high) 
        result = defn.value
    }
    return result
  }
}

class Main
{
  public static Void main ()
  {
    table := ">=  0.00  <  0.06  :=  0.10
              >=  0.06  <  0.11  :=  0.18
              >=  0.11  <  0.16  :=  0.26
              >=  0.16  <  0.21  :=  0.32
              >=  0.21  <  0.26  :=  0.38
              >=  0.26  <  0.31  :=  0.44
              >=  0.31  <  0.36  :=  0.50
              >=  0.36  <  0.41  :=  0.54
              >=  0.41  <  0.46  :=  0.58
              >=  0.46  <  0.51  :=  0.62
              >=  0.51  <  0.56  :=  0.66
              >=  0.56  <  0.61  :=  0.70
              >=  0.61  <  0.66  :=  0.74
              >=  0.66  <  0.71  :=  0.78
              >=  0.71  <  0.76  :=  0.82
              >=  0.76  <  0.81  :=  0.86
              >=  0.81  <  0.86  :=  0.90
              >=  0.86  <  0.91  :=  0.94
              >=  0.91  <  0.96  :=  0.98
              >=  0.96  <  1.01  :=  1.00"
    converter := PriceConverter (table)
    10.times  // simple test with random values
    { 
      price := (0..100).random.toFloat / 100
      echo ("$price -> ${converter.convert (price)}")
    }
  }
}

Forth

A floating-point version wouldn't be hard -- four words would change ( , @ @ cell+ -to- f, f@ f@ float+ ), EVALUATE would be replaced with a small word that forced a floating-point interpretation, and the return stack would not be used in ROUND -- but it would be strikingly unusual. See this page's discussion.

: as begin parse-word dup while evaluate , repeat 2drop ;

create bounds   as  96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11  6  0
create official as 100 98 94 90 86 82 78 74 70 66 62 58 54 50 44 38 32 26 18 10

: official@ ( a-bounds -- +n )
  \ (a+n) - a + b = (a+n) + (b - a) = (b+n)
  [ official bounds - ] literal + @ ;

: round ( n-cents -- n-cents' )
  >r bounds begin dup @ r@ > while cell+ repeat
  r> drop official@ ;

This one is done in the spirit of "Thinking Forth" and doesn't use any tables at all.

: ?adjust 1+ over and if 2* 15 and >r 2 - r> then ;
: accumulate >r dup >r + r> r> ;
: classify dup 0> if 1- then 5 / ;
: calculate do i ?adjust accumulate loop drop drop 100 min ;
: normalize classify >r 0 10 2 r> 1+ 0 calculate ;
: print s>d <# # # [char] . hold #s #> type ;

: test cr 101 0 ?do i print i 2 spaces normalize print cr 5 +loop ;

test

Output:

Fortran

Works with: Fortran version 90 and later

program price_fraction

  implicit none
  integer, parameter :: i_max = 10
  integer :: i
  real, dimension (20), parameter :: in =                           &
    & (/0.00, 0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, &
    &   0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96/)
  real, dimension (20), parameter :: out =                          &
    & (/0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, &
    &   0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00/)
  real :: r

  do i = 1, i_max
    call random_number (r)
    write (*, '(f8.6, 1x, f4.2)') r, out (maxloc (in, r >= in))
  end do

end program price_fraction

Output:

0.997560 1.00
0.566825 0.70
0.965915 1.00
0.747928 0.82
0.367391 0.54
0.480637 0.62
0.073754 0.18
0.005355 0.10
0.347081 0.50
0.342244 0.50

FutureBasic

local fn PriceFraction( price as double ) as double
  double result
  
  if price < 0.00 or price > 1.00 then exit fn = price
  if price < 0.06 then exit fn = 0.10
  if price < 0.11 then exit fn = 0.18
  if price < 0.16 then exit fn = 0.26
  if price < 0.21 then exit fn = 0.32
  if price < 0.26 then exit fn = 0.38
  if price < 0.31 then exit fn = 0.44
  if price < 0.36 then exit fn = 0.50
  if price < 0.41 then exit fn = 0.54
  if price < 0.46 then exit fn = 0.58
  if price < 0.51 then exit fn = 0.62
  if price < 0.56 then exit fn = 0.66
  if price < 0.61 then exit fn = 0.70
  if price < 0.66 then exit fn = 0.74
  if price < 0.71 then exit fn = 0.78
  if price < 0.76 then exit fn = 0.82
  if price < 0.81 then exit fn = 0.86
  if price < 0.86 then exit fn = 0.90
  if price < 0.91 then exit fn = 0.94
  if price < 0.96 then exit fn = 0.98
  result = 1.00
end fn = result

void local fn GetPriceFractions
  NSUInteger i
  
  for i = 1 to 100
    double d = i/100.0
    printf @"%.2f -> %.2f\t\b", d, fn PriceFraction( d )
    if i mod 5 == 0 then print
  next
end fn

fn GetPriceFractions

NSLog( @"%@", fn WindowPrintViewString( 1 ) )

HandleEvents

Output:

0.01 -> 0.10	0.02 -> 0.10	0.03 -> 0.10	0.04 -> 0.10	0.05 -> 0.10	
0.06 -> 0.18	0.07 -> 0.18	0.08 -> 0.18	0.09 -> 0.18	0.10 -> 0.18	
0.11 -> 0.26	0.12 -> 0.26	0.13 -> 0.26	0.14 -> 0.26	0.15 -> 0.26	
0.16 -> 0.32	0.17 -> 0.32	0.18 -> 0.32	0.19 -> 0.32	0.20 -> 0.32	
0.21 -> 0.38	0.22 -> 0.38	0.23 -> 0.38	0.24 -> 0.38	0.25 -> 0.38	
0.26 -> 0.44	0.27 -> 0.44	0.28 -> 0.44	0.29 -> 0.44	0.30 -> 0.44	
0.31 -> 0.50	0.32 -> 0.50	0.33 -> 0.50	0.34 -> 0.50	0.35 -> 0.50	
0.36 -> 0.54	0.37 -> 0.54	0.38 -> 0.54	0.39 -> 0.54	0.40 -> 0.54	
0.41 -> 0.58	0.42 -> 0.58	0.43 -> 0.58	0.44 -> 0.58	0.45 -> 0.58	
0.46 -> 0.62	0.47 -> 0.62	0.48 -> 0.62	0.49 -> 0.62	0.50 -> 0.62	
0.51 -> 0.66	0.52 -> 0.66	0.53 -> 0.66	0.54 -> 0.66	0.55 -> 0.66	
0.56 -> 0.70	0.57 -> 0.70	0.58 -> 0.70	0.59 -> 0.70	0.60 -> 0.70	
0.61 -> 0.74	0.62 -> 0.74	0.63 -> 0.74	0.64 -> 0.74	0.65 -> 0.74	
0.66 -> 0.78	0.67 -> 0.78	0.68 -> 0.78	0.69 -> 0.78	0.70 -> 0.78	
0.71 -> 0.82	0.72 -> 0.82	0.73 -> 0.82	0.74 -> 0.82	0.75 -> 0.82	
0.76 -> 0.86	0.77 -> 0.86	0.78 -> 0.86	0.79 -> 0.86	0.80 -> 0.86	
0.81 -> 0.90	0.82 -> 0.90	0.83 -> 0.90	0.84 -> 0.90	0.85 -> 0.90	
0.86 -> 0.94	0.87 -> 0.94	0.88 -> 0.94	0.89 -> 0.94	0.90 -> 0.94	
0.91 -> 0.98	0.92 -> 0.98	0.93 -> 0.98	0.94 -> 0.98	0.95 -> 0.98	
0.96 -> 1.00	0.97 -> 1.00	0.98 -> 1.00	0.99 -> 1.00	1.00 -> 1.00

Go

package main

import "fmt"

func pf(v float64) float64 {
    switch {
    case v < .06:
        return .10
    case v < .11:
        return .18
    case v < .16:
        return .26
    case v < .21:
        return .32
    case v < .26:
        return .38
    case v < .31:
        return .44
    case v < .36:
        return .50
    case v < .41:
        return .54
    case v < .46:
        return .58
    case v < .51:
        return .62
    case v < .56:
        return .66
    case v < .61:
        return .70
    case v < .66:
        return .74
    case v < .71:
        return .78
    case v < .76:
        return .82
    case v < .81:
        return .86
    case v < .86:
        return .90
    case v < .91:
        return .94
    case v < .96:
        return .98
    }
    return 1
}

func main() {
    tests := []float64{0.3793, 0.4425, 0.0746, 0.6918, 0.2993,
        0.5486, 0.7848, 0.9383, 0.2292, 0.9760}
    for _, v := range tests {
        fmt.Printf("%0.4f -> %0.2f\n", v, pf(v))
    }
}

0.3793 -> 0.54
0.4425 -> 0.58
0.0746 -> 0.18
0.6918 -> 0.78
0.2993 -> 0.44
0.5486 -> 0.66
0.7848 -> 0.86
0.9383 -> 0.98
0.2292 -> 0.38
0.9760 -> 1.00

Groovy

def priceFraction(value) {
    assert value >= 0.0 && value <= 1.0

    def priceMappings = [(0.06): 0.10, (0.11): 0.18, (0.16): 0.26, (0.21): 0.32, (0.26): 0.38,
         (0.31): 0.44, (0.36): 0.50, (0.41): 0.54, (0.46): 0.58, (0.51): 0.62,
         (0.56): 0.66, (0.61): 0.70, (0.66): 0.74, (0.71): 0.78, (0.76): 0.82,
         (0.81): 0.86, (0.86): 0.90, (0.91): 0.94, (0.96): 0.98]

    for (price in priceMappings.keySet()) {
        if (value < price) return priceMappings[price]
    }
    1.00
}

for (def v = 0.00; v <= 1.00; v += 0.01) {
    println "$v --> ${priceFraction(v)}"
}

Output:

0.00 --> 0.10
0.01 --> 0.10
0.02 --> 0.10
0.03 --> 0.10
0.04 --> 0.10
0.05 --> 0.10
0.06 --> 0.18
0.07 --> 0.18
0.08 --> 0.18
0.09 --> 0.18
0.10 --> 0.18
0.11 --> 0.26
0.12 --> 0.26
0.13 --> 0.26
0.14 --> 0.26
0.15 --> 0.26
0.16 --> 0.32
0.17 --> 0.32
0.18 --> 0.32
0.19 --> 0.32
0.20 --> 0.32
0.21 --> 0.38
0.22 --> 0.38
0.23 --> 0.38
0.24 --> 0.38
0.25 --> 0.38
0.26 --> 0.44
0.27 --> 0.44
0.28 --> 0.44
0.29 --> 0.44
0.30 --> 0.44
0.31 --> 0.50
0.32 --> 0.50
0.33 --> 0.50
0.34 --> 0.50
0.35 --> 0.50
0.36 --> 0.54
0.37 --> 0.54
0.38 --> 0.54
0.39 --> 0.54
0.40 --> 0.54
0.41 --> 0.58
0.42 --> 0.58
0.43 --> 0.58
0.44 --> 0.58
0.45 --> 0.58
0.46 --> 0.62
0.47 --> 0.62
0.48 --> 0.62
0.49 --> 0.62
0.50 --> 0.62
0.51 --> 0.66
0.52 --> 0.66
0.53 --> 0.66
0.54 --> 0.66
0.55 --> 0.66
0.56 --> 0.70
0.57 --> 0.70
0.58 --> 0.70
0.59 --> 0.70
0.60 --> 0.70
0.61 --> 0.74
0.62 --> 0.74
0.63 --> 0.74
0.64 --> 0.74
0.65 --> 0.74
0.66 --> 0.78
0.67 --> 0.78
0.68 --> 0.78
0.69 --> 0.78
0.70 --> 0.78
0.71 --> 0.82
0.72 --> 0.82
0.73 --> 0.82
0.74 --> 0.82
0.75 --> 0.82
0.76 --> 0.86
0.77 --> 0.86
0.78 --> 0.86
0.79 --> 0.86
0.80 --> 0.86
0.81 --> 0.90
0.82 --> 0.90
0.83 --> 0.90
0.84 --> 0.90
0.85 --> 0.90
0.86 --> 0.94
0.87 --> 0.94
0.88 --> 0.94
0.89 --> 0.94
0.90 --> 0.94
0.91 --> 0.98
0.92 --> 0.98
0.93 --> 0.98
0.94 --> 0.98
0.95 --> 0.98
0.96 --> 1.00
0.97 --> 1.00
0.98 --> 1.00
0.99 --> 1.00
1.00 --> 1.00

Haskell

price_fraction n
  | n < 0 || n > 1 = error "Values must be between 0 and 1."
  | n < 0.06 = 0.10
  | n < 0.11 = 0.18
  | n < 0.16 = 0.26
  | n < 0.21 = 0.32
  | n < 0.26 = 0.38
  | n < 0.31 = 0.44
  | n < 0.36 = 0.50
  | n < 0.41 = 0.54
  | n < 0.46 = 0.58
  | n < 0.51 = 0.62
  | n < 0.56 = 0.66
  | n < 0.61 = 0.70
  | n < 0.66 = 0.74
  | n < 0.71 = 0.78
  | n < 0.76 = 0.82
  | n < 0.81 = 0.86
  | n < 0.86 = 0.90
  | n < 0.91 = 0.94
  | n < 0.96 = 0.98
  | otherwise = 1.00

Alternative

Translation of: OCaml

:

table = [
    (0.06, 0.10),   (0.11, 0.18),   (0.16, 0.26),   (0.21, 0.32),   (0.26, 0.38),
    (0.31, 0.44),   (0.36, 0.50),   (0.41, 0.54),   (0.46, 0.58),   (0.51, 0.62),
    (0.56, 0.66),   (0.61, 0.70),   (0.66, 0.74),   (0.71, 0.78),   (0.76, 0.82),
    (0.81, 0.86),   (0.86, 0.90),   (0.91, 0.94),   (0.96, 0.98),   (1.01, 1.00),
  ]

price_fraction n
  | n < 0 || n > 1 = error "Values must be between 0 and 1."
  | otherwise = snd $ head $ dropWhile ((<= n) . fst) table

HicEst

DIMENSION upperbound(20), rescaleTo(20), temp(20)
upperbound = (.06,.11,.16,.21,.26,.31,.36,.41,.46,.51,.56,.61,.66,.71,.76,.81,.86,.91,.96,1.01)
rescaleTo =  (.10,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.90,.94,.98,1.00)

DO test = 1, 10
  value = RAN(0.5, 0.5)
  temp = value > upperbound
  PriceFraction = rescaleTo( INDEX(temp, 0) )
  WRITE(Format="F8.6, F6.2") value, PriceFraction
ENDDO

0.589230  0.70
0.017623  0.10
0.314343  0.50
0.553303  0.66
0.676283  0.78
0.016883  0.10
0.265656  0.44
0.460880  0.62
0.837450  0.90
0.228953  0.38

Icon and Unicon

record Bounds(low,high,new)

# rescale given value according to a list of bounds
procedure rescale (i, bounds)
  every bound := !bounds do 
    if bound.low <= i < bound.high
      then return bound.new
  return fail # could not find i in bounds
end

procedure main ()
  bounds := [
    Bounds(0.00, 0.06, 0.10),
    Bounds(0.06, 0.11, 0.18),
    Bounds(0.11, 0.16, 0.26),
    Bounds(0.16, 0.21, 0.32),
    Bounds(0.21, 0.26, 0.38),
    Bounds(0.26, 0.31, 0.44),
    Bounds(0.31, 0.36, 0.50),
    Bounds(0.36, 0.41, 0.54),
    Bounds(0.41, 0.46, 0.58),
    Bounds(0.46, 0.51, 0.62),
    Bounds(0.51, 0.56, 0.66),
    Bounds(0.56, 0.61, 0.70),
    Bounds(0.61, 0.66, 0.74),
    Bounds(0.66, 0.71, 0.78),
    Bounds(0.71, 0.76, 0.82),
    Bounds(0.76, 0.81, 0.86),
    Bounds(0.81, 0.86, 0.90),
    Bounds(0.86, 0.91, 0.94),
    Bounds(0.91, 0.96, 0.98),
    Bounds(0.96, 1.01, 1.00)
  ]

  # test the procedure
  every i := 0.00 to 1.00 by 0.1 do {
    write (i || " rescaled is " || rescale(i, bounds))
  }
end

Output:

0.0 rescaled is 0.1
0.1 rescaled is 0.18
0.2 rescaled is 0.32
0.3 rescaled is 0.44
0.4 rescaled is 0.54
0.5 rescaled is 0.62
0.6 rescaled is 0.7
0.7 rescaled is 0.78
0.8 rescaled is 0.86
0.9 rescaled is 0.94
1.0 rescaled is 1.0

Inform 7

Inform doesn't have native floating-point support; this version uses fixed point numbers with two decimal places.

Home is a room.

Price is a kind of value. 0.99 specifies a price.

Table of Price Standardization
upper bound	replacement
0.06		0.10
0.11		0.18
0.16		0.26
0.21		0.32
0.26		0.38
0.31		0.44
0.36		0.50
0.41		0.54
0.46		0.58
0.51		0.62
0.56		0.66
0.61		0.70
0.66		0.74
0.71		0.78
0.76		0.82
0.81		0.86
0.86		0.90
0.91		0.94
0.96		0.98
1.01		1.00

To decide which price is the standardized value of (P - price):
	repeat with N running from 1 to the number of rows in the Table of Price Standardization:
		choose row N in the Table of Price Standardization;
		if P is less than the upper bound entry, decide on the replacement entry.

When play begins:
	repeat with N running from 1 to 5:
		let P be a random price between 0.00 and 1.00;
		say "[P] -> [standardized value of P].";
	end the story.

J

Solution:

le  =: -0.96 0.91 0.86 0.81 0.76 0.71 0.66 0.61 0.56 0.51 0.46 0.41 0.36 0.31 0.26 0.21 0.16 0.11 0.06 0.0
out =:  1.00 0.98 0.94 0.90 0.86 0.82 0.78 0.74 0.70 0.66 0.62 0.58 0.54 0.50 0.44 0.38 0.32 0.26 0.18 0.1

priceFraction =:  out {~ le I. -

Example:

   priceFraction 0.34 0.070145 0.06 0.05 0.50214 0.56 1 0.99 0   
0.5 0.18 0.18 0.1 0.62 0.7 1 1 0.1

This implementation performs a binary search on the boundary values, and then uses the resulting index to select from the result values.

To prevent J's binary search from doing the wrong thing for values equal to a boundary, both the boundary values and the search value are negated.

Java

import java.util.Random;

public class Main {
	private static float priceFraction(float f) {
		if (0.00f <= f && f < 0.06f) return 0.10f;
		else if (f < 0.11f) return 0.18f;
		else if (f < 0.16f) return 0.26f;
		else if (f < 0.21f) return 0.32f;
		else if (f < 0.26f) return 0.38f;
		else if (f < 0.31f) return 0.44f;
		else if (f < 0.36f) return 0.50f;
		else if (f < 0.41f) return 0.54f;
		else if (f < 0.46f) return 0.58f;
		else if (f < 0.51f) return 0.62f;
		else if (f < 0.56f) return 0.66f;
		else if (f < 0.61f) return 0.70f;
		else if (f < 0.66f) return 0.74f;
		else if (f < 0.71f) return 0.78f;
		else if (f < 0.76f) return 0.82f;
		else if (f < 0.81f) return 0.86f;
		else if (f < 0.86f) return 0.90f;
		else if (f < 0.91f) return 0.94f;
		else if (f < 0.96f) return 0.98f;
		else if (f < 1.01f) return 1.00f;
		else throw new IllegalArgumentException();
	}

	public static void main(String[] args) {
		Random rnd = new Random();
		for (int i = 0; i < 5; i++) {
			float f = rnd.nextFloat();
			System.out.format("%8.6f -> %4.2f%n", f, priceFraction(f));
		}
	}
}

Output:

0.149969 -> 0.26
0.310605 -> 0.50
0.616683 -> 0.74
0.194047 -> 0.32
0.724852 -> 0.82

JavaScript

In the task definition, the first step is 0.06, the rest are 0.05 so a re-factoring can subtract 0.01 from the value and divide by 0.05 to get the step.

Working with decimal numbers in JavaScript has issues, e.g. 0.06 - 0.01 = 0.049999999999999996 due to using IEEE 754 double precision numbers that can't accurately represent all decimals. So values are multiplied by 100 and integer arithmetic is used.

Note that multiplying a string by a number produces a number, the bitwise OR (|) truncates floating point numbers to integer, making it a concise replacement for Math.floor.

Passing a value outside the range 0 <= x < 1.01 will return undefined.

function getScaleFactor(v) {

  var values = ['0.10','0.18','0.26','0.32','0.38','0.44','0.50','0.54',
                '0.58','0.62','0.66','0.70','0.74','0.78','0.82','0.86',
                '0.90','0.94','0.98','1.00'];

  return values[(v * 100 - 1) / 5 | 0];
}

jq

The solution given here is based on the JavaScript solution.

def getScaleFactor:
  ["0.10","0.18","0.26","0.32","0.38","0.44","0.50","0.54",
   "0.58","0.62","0.66","0.70","0.74","0.78","0.82","0.86",
   "0.90","0.94","0.98","1.00"] as $values
  | $values[ (. * 100 - 1) / 5 | floor ] ;

The full coverage test as given in the Ada example:

def test:
  (range(0;10)  | "0.0\(.) -> \( 0.01 * . | getScaleFactor)"),
  (range(10;100) | "0.\(.) -> \( 0.01 * . | getScaleFactor)");

test

Run the test, showing the first few lines of output:

$ jq -n -r -f Price_fraction.jq
0.00 -> 1.00
0.01 -> 0.10
0.02 -> 0.10
0.03 -> 0.10
0.04 -> 0.10
0.05 -> 0.10
0.06 -> 0.18
0.07 -> 0.18
0.08 -> 0.18
0.09 -> 0.18
0.10 -> 0.18
0.11 -> 0.26
...

Julia

This solution is somewhat straightforward but does highlight a couple of Julia features. The interval cut-offs and values are exactly represented by rational numbers. The interval to which an input value belongs is identified by applying the findfirst (true value) function to an element-wise comparison (.<) of this value to the cut-off array.

const PFCUT = [6:5:101]//100
const PFVAL = [10:8:26, 32:6:50, 54:4:98, 100]//100

function pricefraction{T<:FloatingPoint}(a::T)
    zero(T) <= a || error("a = ", a, ", but it must be >= 0.")
    a <= one(T) || error("a = ", a, ", but it must be <= 1.")
    convert(T, PFVAL[findfirst(a .< PFCUT)])
end

test = [0.:0.05:1., 0.51, 0.56, 0.61, rand(), rand(), rand(), rand()]

println("Testing the price fraction function")
for t in test
    println(@sprintf "    %.4f -> %.4f" t pricefraction(t))
end

Output:

Testing the price fraction function
    0.0000 -> 0.1000
    0.0500 -> 0.1000
    0.1000 -> 0.1800
    0.1500 -> 0.2600
    0.2000 -> 0.3200
    0.2500 -> 0.3800
    0.3000 -> 0.4400
    0.3500 -> 0.5000
    0.4000 -> 0.5400
    0.4500 -> 0.5800
    0.5000 -> 0.6200
    0.5500 -> 0.6600
    0.6000 -> 0.7000
    0.6500 -> 0.7400
    0.7000 -> 0.7800
    0.7500 -> 0.8200
    0.8000 -> 0.8600
    0.8500 -> 0.9000
    0.9000 -> 0.9400
    0.9500 -> 0.9800
    1.0000 -> 1.0000
    0.5100 -> 0.6600
    0.5600 -> 0.7000
    0.6100 -> 0.7400
    0.5603 -> 0.7000
    0.9812 -> 1.0000
    0.5127 -> 0.6600
    0.4821 -> 0.6200

K

Translation of the J solution:

le:- 0.96 0.91 0.86 0.81 0.76 0.71 0.66 0.61 0.56 0.51 0.46 0.41 0.36 0.31 0.26 0.21 0.16 0.11 0.06 0.0
out: 1.00 0.98 0.94 0.90 0.86 0.82 0.78 0.74 0.70 0.66 0.62 0.58 0.54 0.50 0.44 0.38 0.32 0.26 0.18 0.1

pf:{out@_bin[le;-x]}'

Output:

   pf 0.6094701 0.5003597 0.8512954 0.08951883 0.6868076
0.7 0.62 0.9 0.18 0.78

Kotlin

// version 1.0.6

fun rescale(price: Double): Double = 
    when {
        price < 0.06 ->  0.10
        price < 0.11 ->  0.18
        price < 0.16 ->  0.26
        price < 0.21 ->  0.32
        price < 0.26 ->  0.38
        price < 0.31 ->  0.44
        price < 0.36 ->  0.50
        price < 0.41 ->  0.54
        price < 0.46 ->  0.58
        price < 0.51 ->  0.62
        price < 0.56 ->  0.66
        price < 0.61 ->  0.70
        price < 0.66 ->  0.74
        price < 0.71 ->  0.78
        price < 0.76 ->  0.82
        price < 0.81 ->  0.86
        price < 0.86 ->  0.90
        price < 0.91 ->  0.94
        price < 0.96 ->  0.98
        else         ->  1.00
    }

fun main(args: Array<String>) {
    var d: Double
    for (i in 1..100) {
        d = i / 100.0
        print(String.format("%4.2f -> %4.2f  ", d, rescale(d)))
        if (i % 5 == 0) println()
    }  
}

Output:

0.01 -> 0.10  0.02 -> 0.10  0.03 -> 0.10  0.04 -> 0.10  0.05 -> 0.10
0.06 -> 0.18  0.07 -> 0.18  0.08 -> 0.18  0.09 -> 0.18  0.10 -> 0.18
0.11 -> 0.26  0.12 -> 0.26  0.13 -> 0.26  0.14 -> 0.26  0.15 -> 0.26
0.16 -> 0.32  0.17 -> 0.32  0.18 -> 0.32  0.19 -> 0.32  0.20 -> 0.32
0.21 -> 0.38  0.22 -> 0.38  0.23 -> 0.38  0.24 -> 0.38  0.25 -> 0.38
0.26 -> 0.44  0.27 -> 0.44  0.28 -> 0.44  0.29 -> 0.44  0.30 -> 0.44
0.31 -> 0.50  0.32 -> 0.50  0.33 -> 0.50  0.34 -> 0.50  0.35 -> 0.50
0.36 -> 0.54  0.37 -> 0.54  0.38 -> 0.54  0.39 -> 0.54  0.40 -> 0.54
0.41 -> 0.58  0.42 -> 0.58  0.43 -> 0.58  0.44 -> 0.58  0.45 -> 0.58
0.46 -> 0.62  0.47 -> 0.62  0.48 -> 0.62  0.49 -> 0.62  0.50 -> 0.62
0.51 -> 0.66  0.52 -> 0.66  0.53 -> 0.66  0.54 -> 0.66  0.55 -> 0.66
0.56 -> 0.70  0.57 -> 0.70  0.58 -> 0.70  0.59 -> 0.70  0.60 -> 0.70
0.61 -> 0.74  0.62 -> 0.74  0.63 -> 0.74  0.64 -> 0.74  0.65 -> 0.74
0.66 -> 0.78  0.67 -> 0.78  0.68 -> 0.78  0.69 -> 0.78  0.70 -> 0.78
0.71 -> 0.82  0.72 -> 0.82  0.73 -> 0.82  0.74 -> 0.82  0.75 -> 0.82
0.76 -> 0.86  0.77 -> 0.86  0.78 -> 0.86  0.79 -> 0.86  0.80 -> 0.86
0.81 -> 0.90  0.82 -> 0.90  0.83 -> 0.90  0.84 -> 0.90  0.85 -> 0.90
0.86 -> 0.94  0.87 -> 0.94  0.88 -> 0.94  0.89 -> 0.94  0.90 -> 0.94
0.91 -> 0.98  0.92 -> 0.98  0.93 -> 0.98  0.94 -> 0.98  0.95 -> 0.98
0.96 -> 1.00  0.97 -> 1.00  0.98 -> 1.00  0.99 -> 1.00  1.00 -> 1.00

langur

Langur uses decimal floating point.

val .pricefrac = fn(.f) switch[and] .f {
    case >= 0.00, < 0.06: 0.10
    case >= 0.06, < 0.11: 0.18
    case >= 0.11, < 0.16: 0.26
    case >= 0.16, < 0.21: 0.32
    case >= 0.21, < 0.26: 0.38
    case >= 0.26, < 0.31: 0.44
    case >= 0.31, < 0.36: 0.50
    case >= 0.36, < 0.41: 0.54
    case >= 0.41, < 0.46: 0.58
    case >= 0.46, < 0.51: 0.62
    case >= 0.51, < 0.56: 0.66
    case >= 0.56, < 0.61: 0.70
    case >= 0.61, < 0.66: 0.74
    case >= 0.66, < 0.71: 0.78
    case >= 0.71, < 0.76: 0.82
    case >= 0.76, < 0.81: 0.86
    case >= 0.81, < 0.86: 0.90
    case >= 0.86, < 0.91: 0.94
    case >= 0.91, < 0.96: 0.98
    case >= 0.96, <= 1.00: 1.00
    default: throw "bad data"
}

writeln .pricefrac(0.17)
writeln .pricefrac(0.71)

Output:

0.32
0.82

Lua

scaleTable = {
    {0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32},
    {0.26, 0.38}, {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54},
    {0.46, 0.58}, {0.51, 0.62}, {0.56, 0.66}, {0.61, 0.70},
    {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, {0.81, 0.86},
    {0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00}
}
    
function rescale (price)
    if price < 0 or price > 1 then return "Out of range!" end
    for k, v in pairs(scaleTable) do
        if price < v[1] then return v[2] end
    end
end

math.randomseed(os.time())
for i = 1, 5 do
    rnd = math.random()
    print("Random value:", rnd)
    print("Adjusted price:", rescale(rnd))
    print()
end

Output:

Random value:   0.61946413522022
Adjusted price: 0.74

Random value:   0.81141947958698
Adjusted price: 0.9

Random value:   0.55691473099814
Adjusted price: 0.66

Random value:   0.19704311677601
Adjusted price: 0.32

Random value:   0.36528313938816
Adjusted price: 0.54

M2000 Interpreter

Derived from BASIC

Module PriceFraction {
	Currency i
	Print $("0.00"),
	for i=0@ to 1@ step .10@
		Print i, @PriceFraction(i)
	next
	Print $(""),
	
	function PriceFraction(price as currency)
	    select case price
	        case < 0
	            = price
	        case < .06
	            = .1
	        case < .11
	            = .18
	        case < .16
	            = .26
	        case < .21
	            = .32
	        case < .26
	            = .38
	        case < .31
	            = .44
	        case < .36
	            = .5
	        case < .41
	            = .54
	        case < .46
	            = .58
	        case < .51
	            = .62
	        case < .56
	            = .66
	        case < .61
	            = .7
	        case < .66
	            = .74
	        case < .71
	            = .78
	        case < .76
	            = .82
	        case < .81
	            = .86
	        case < .86
	            = .9
	        case < .91
	            = .94
	        case < .96
	            = .98
	        case < 1.01
	            = 1!
	        case else
	            = price
	    end select
	end function
}
PriceFraction

Output:

     0.00     0.10
     0.10     0.18
     0.20     0.32
     0.30     0.44
     0.40     0.54
     0.50     0.62
     0.60     0.70
     0.70     0.78
     0.80     0.86
     0.90     0.94
     1.00     1.00

Maple

priceFraction := proc(price)
	local values, standard, newPrice, i;
	values := [0, 0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61,
			 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01];
	standard := [0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70,
			   0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00];
	for i to numelems(standard) do
		if price >= values[i] and price < values[i+1] then
			newPrice := standard[i];
		end if;
	end do;
	printf("%f --> %.2f\n", price, newPrice);
end proc:

randomize():
for i to 5 do
	priceFraction (rand(0.0..1.0)());
end do;

Output:

0.524386 --> 0.66
0.887957 --> 0.94
0.670196 --> 0.78
0.875601 --> 0.94
0.540447 --> 0.66

Mathematica/Wolfram Language

PriceFraction[x_]:=Piecewise[{{.1, 0 <= x < 0.06}, {.18, x < .11}, {.26,x < 0.16}, 
{.32, x < .21}, {.38, x < .26}, {.44, x < 0.31}, {.5, x < .36}, 
{.54, x < .41}, {.58, x < .46}, {.62, x < .51}, {.66, x < .56}, 
{.70, x < .61}, {.74, x < .66}, {.78, x < .71}, {.82, x < .76},
{.86, x < .81}, {.90, x < .86}, {.94, x < .91}, {.98, x < .96}}, 1]

MATLAB / Octave

  function y = rescale(x) 
	 
     L = [0,.06:.05:1.02];
     V = [.1,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.9,.94,.98,1];

     y = x; 
     for k=1:numel(x); 
        y(k) = V(sum(L<=x(k)));
     end;
  end;

   t=0:0.001:1;
   plot(t,rescale(t));

Mercury

:- module price.
:- interface.
:- import_module int.
:- type price == int.
:- func standard(price) = price.

:- implementation.
:- import_module require, list.

standard(P) = SP :-
        require(P >= 0, "P must be positive"),
        Cents = P `mod` 100,
        P + adjust(Cents) = SP.

:- func adjust(int) = int.
adjust(Cents) = adjust(Cents, rules).

:- func adjust(int, list(price_rule)) = int.
adjust(_, []) = unexpected("price", "adjust/2", "exhausted rules").
adjust(N, [rule(Low, High, To)|T]) = R :-
        ( N >= Low, N < High -> To - N = R ; adjust(N, T) = R ).

:- type price_rule ---> rule(int, int, int).
:- func rules = list(price_rule).
rules = [rule(00, 06, 10),
        rule(06, 11, 18),
        rule(11, 16, 26),
        rule(16, 21, 32),
        rule(21, 26, 38),
        rule(26, 31, 44),
        rule(31, 36, 50),
        rule(36, 41, 54),
        rule(41, 46, 58),
        rule(46, 51, 62),
        rule(51, 56, 66),
        rule(56, 61, 70),
        rule(61, 66, 74),
        rule(66, 71, 78),
        rule(71, 76, 82),
        rule(76, 81, 86),
        rule(81, 86, 90),
        rule(86, 91, 94),
        rule(91, 96, 98),
        rule(96, 101, 100)].

A build system might turn the text of the table into the definition of a hundred-element array of adjustments. In that case,

adjust(Cents) = array.lookup(price_table, Cents).

MUMPS

PRICFRAC(X)
 ;Outputs a specified value dependent upon the input value
 ;The non-inclusive upper limits are encoded in the PFMAX string, and the values
 ;to convert to are encoded in the PFRES string.
 NEW PFMAX,PFRES,I,RESULT
 SET PFMAX=".06^.11^.16^.21^.26^.31^.36^.41^.46^.51^.56^.61^.66^.71^.76^.81^.86^.91^.96^1.01"
 SET PFRES=".10^.18^.26^.32^.38^.44^.50^.54^.58^.62^.66^.70^.74^.78^.82^.86^.90^.94^.98^1.00"
 Q:(X<0)!(X>1.01) ""
 FOR I=1:1:$LENGTH(PFMAX,"^") Q:($DATA(RESULT)'=0)  SET:X<$P(PFMAX,"^",I) RESULT=$P(PFRES,"^",I)
 KILL PFMAX,PFRES,I
 QUIT RESULT

Output:

USER>W $$PRICFRAC^ROSETTA(.04)
.10
USER>W $$PRICFRAC^ROSETTA(.06)
.18
USER>W $$PRICFRAC^ROSETTA(.40)
.54
USER>W $$PRICFRAC^ROSETTA(1.40)
 
USER>W $$PRICFRAC^ROSETTA(.81)
.90

NetRexx

/* NetRexx */
options replace format comments java crossref symbols nobinary

runSample(arg)
return

-- -----------------------------------------------------------------------------
method runSample(arg) public static
  parse arg in_val .
  if in_val \= '' then test_vals = [in_val]
  else                 test_vals = getTestData()

  say 'Input Adjustment'
  loop tv = 0 to test_vals.length - 1
    in_val = test_vals[tv]
    adjust = priceFraction(in_val)
    say in_val.format(null, 2).right(5) adjust.format(null, 2).right(10)
    end tv

  return

-- -----------------------------------------------------------------------------
method priceFraction(in_val) public static
  out_val = -1
  limit_table = getLimitTable()
  limit_table_K = limit_table.length
  loop p1 = 0 to limit_table_K - 1
    pair = limit_table[p1]
    hi_limit = pair[0]
    adjustmt = pair[1]
    if in_val < hi_limit then do
      out_val = adjustmt
      leave p1
      end
    end p1
  if out_val = -1 then signal IllegalArgumentException('Input' in_val 'is outside of acceptable range.')

  return out_val

-- -----------------------------------------------------------------------------
method getLimitTable() public static returns Rexx[,]
  limit_table = [ -
    [0.06, 0.10], [0.11, 0.18], [0.16, 0.26], [0.21, 0.32], [0.26, 0.38], -
    [0.31, 0.44], [0.36, 0.50], [0.41, 0.54], [0.46, 0.58], [0.51, 0.62], -
    [0.56, 0.66], [0.61, 0.70], [0.66, 0.74], [0.71, 0.78], [0.76, 0.82], -
    [0.81, 0.86], [0.86, 0.90], [0.91, 0.94], [0.96, 0.98], [1.01, 1.00]  -
  ]
  return limit_table

-- -----------------------------------------------------------------------------
method getTestData() private static returns Rexx[]
  test_vals = Rexx[5]
  rng = Random(1024)
  loop tv = 0 to test_vals.length - 1
    test_vals[tv] = rng.nextFloat()
    end tv
  return test_vals

Output:

Input Adjustment
 0.64       0.74
 0.32       0.50
 0.85       0.90
 0.93       0.98
 0.62       0.74

Nim

import random, strformat

# Representation of a standard value as an int (actual value * 100).
type StandardValue = distinct int

proc `<`(a, b: StandardValue): bool {.borrow.}

const Pricemap = [10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100]


proc toStandardValue(f: float): StandardValue =
  ## Convert a float to a standard value (decimal value multiplied by 100).
  ## Index: 0.01..0.05 -> 0, 0.06..0.10 -> 1, 0.11..0.15 -> 2...
  var value = int(f * 100)
  if value == 0: return StandardValue(10)
  dec value
  # Increment index every 5 of value, so value in 1..100 translates to index in 0..19.
  let index = 2 * (value div 10) + (value mod 10) div 5
  result = StandardValue(Pricemap[index])


proc `$`(price: StandardValue): string =
  ## Return the string representation of a standard value.
  if price < StandardValue(10): "0.0" & $int(price)
  elif price < StandardValue(100): "0." & $int(price)
  else: "1.00"


when isMainModule:
  randomize()
  for _ in 0 .. 10:
    let price = rand(1.01)
    echo &"Price for {price:.2f} is {price.toStandardValue()}"

Output:

A random output looking something like this:

Price for 0.88 is 0.94
Price for 0.58 is 0.70
Price for 0.67 is 0.78
Price for 0.53 is 0.66
Price for 0.56 is 0.66
Price for 0.02 is 0.10
Price for 0.61 is 0.70
Price for 0.41 is 0.58
Price for 0.22 is 0.38
Price for 0.91 is 0.98
Price for 0.42 is 0.58

Objeck

Translation of: C#

class PriceFraction {
  function : Main(args : String[]) ~ Nil {
    for(i := 0; i < 5; i++;) {
      f := Float->Random();
      r := SpecialRound(f);
      "{$f} -> {$r}"->PrintLine();
    };
  }

  function : SpecialRound(inValue : Float) ~ Float {
    if (inValue > 1) {
      return 1;
    };

    splitters := [  
      0.00 , 0.06 , 0.11 , 0.16 , 0.21 , 
      0.26 , 0.31 , 0.36 , 0.41 , 0.46 , 
      0.51 , 0.56 , 0.61 , 0.66 , 0.71 , 
      0.76 , 0.81 , 0.86 , 0.91 , 0.96 ];

    replacements := [ 
      0.10 , 0.18 , 0.26 , 0.32 , 0.38 ,
      0.44 , 0.50 , 0.54 , 0.58 , 0.62 , 
      0.66 , 0.70 , 0.74 , 0.78 , 0.82 , 
      0.86 , 0.90 , 0.94 , 0.98 , 1.00 ];

    for(x := 0; x < splitters->Size() - 1; x+=1;) {
      if (inValue >= splitters[x] & inValue < splitters[x + 1]) {
        return replacements[x];
      };
    };

    return inValue;
  }
}

Output:

0.317901 -> 0.5
0.691109 -> 0.78
0.790891 -> 0.86
0.269922 -> 0.44
0.690891 -> 0.78

OCaml

let price_fraction v =
  if v < 0.0 || v >= 1.01 then
    invalid_arg "price_fraction";
  let rec aux = function
  | (x,r)::tl ->
      if v < x then r
      else aux tl
  | [] -> assert false
  in
  aux [
    0.06, 0.10;   0.11, 0.18;   0.16, 0.26;   0.21, 0.32;   0.26, 0.38;
    0.31, 0.44;   0.36, 0.50;   0.41, 0.54;   0.46, 0.58;   0.51, 0.62;
    0.56, 0.66;   0.61, 0.70;   0.66, 0.74;   0.71, 0.78;   0.76, 0.82;
    0.81, 0.86;   0.86, 0.90;   0.91, 0.94;   0.96, 0.98;   1.01, 1.00;
  ]

let () =
  let ok_tests = [
    (0.3793, 0.54);
    (0.4425, 0.58);
    (0.0746, 0.18);
    (0.6918, 0.78);
    (0.2993, 0.44);
    (0.5486, 0.66);
    (0.7848, 0.86);
    (0.9383, 0.98);
    (0.2292, 0.38);
  ] in
  Printf.printf " input   res   ok\n";
  List.iter (fun (v,ok) ->
    let r = price_fraction v in
    Printf.printf " %6g  %g  %b\n" v r (r = ok);
  ) ok_tests;
;;

Oforth

[.06, .11, .16, .21, .26, .31, .36, .41, .46, .51, .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01] const: IN
[.10, .18, .26, .32, .38, .44, .50, .54, .58, .62, .66, .70, .74, .78, .82, .86, .90, .94, .98, 1.00] const: OUT

: priceFraction(f)
| i |
   IN size loop: i [ f IN at(i) < ifTrue: [ OUT at(i) return ] ]
   null ;

Output:

>[0.7388727, 0.8593103, 0.826687, 0.3444635] map(#priceFraction) .
[0.82, 0.9, 0.9, 0.5] ok

Oz

Using a for-loop with return and a default value for values >= 1.01. For out-of-range input, a "failed value" is returned, i.e. a value that throws an exception when it is accessed.

fun {PriceFraction X}
   OutOfRange = {Value.failed outOfRange(X)}
in
   for Limit#Result in
      [0.00#OutOfRange
       0.06#0.10 0.11#0.18 0.16#0.26 0.21#0.32 0.26#0.38 0.31#0.44 0.36#0.5
       0.41#0.54 0.46#0.58 0.51#0.62 0.56#0.66 0.61#0.70 0.66#0.74 0.71#0.78
       0.76#0.82 0.81#0.86 0.86#0.90 0.91#0.94 0.96#0.98 1.01#1.00
      ]
      return:Return
      default:OutOfRange
   do
      if X < Limit then {Return Result} end 
   end
end

PARI/GP

priceLookup=[6,11,16,21,26,31,41,46,51,56,61,66,71,76,81,86,91,96,101];
priceReplace=[10,18,26,32,38,44,50,54,58,62,66,70,74,78,82,86,90,94,98,100];
pf(x)={
  x*=100;
  for(i=1,19,
    if(x<priceLookup[i], return(priceReplace[i]))
  );
  "nasal demons"
};

Pascal

Program PriceFraction(output);

const
  limit: array [1..20] of real = 
           (0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51,
            0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01);
  price: array [1..20] of real = 
           (0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62,
            0.66, 0.70, 0.74, 0.78, 0.81, 0.86, 0.90, 0.94, 0.98, 1.00);

var
  cost: real;
  i, j: integer;

begin
  randomize;
  for i := 1 to 10 do
  begin
    cost := random;
    j := high(limit);
    while cost < limit[j] do
      dec(j);
    writeln (cost:6:4, ' -> ', price[j+1]:4:2);
  end;
end.

Output:

% ./PriceFraction
0.8145 -> 0.90
0.6347 -> 0.74
0.0464 -> 0.10
0.9603 -> 1.00
0.3629 -> 0.54
0.5074 -> 0.62
0.4516 -> 0.58
0.2340 -> 0.38
0.4142 -> 0.58
0.8327 -> 0.90

Perl

my @table = map [ /([\d\.]+)/g ], split "\n", <<'TBL';
>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00
TBL

sub convert {
        my $money = shift;
        for (@table) {
                return $_->[2] if $_->[0] <= $money and $_->[1] > $money
        }
        die "Can't find currency conversion for $money. Counterfeit?"
}

# try it out
for (1 .. 10) {
        my $m = rand(1);
        printf "%.3f -> %g\n", $m, convert($m);
}

Phix

with javascript_semantics
constant TBL=split("""
>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00""",'\n')
 
sequence limits = {0},
         prices = {-1}
atom pl,lt,plt=0,price
for i=1 to length(TBL) do
    {pl,lt,price} = scanf(TBL[i],">=  %.2f  <  %.2f  :=  %.2f")[1]
    assert(pl==plt)
    plt = lt
    limits = append(limits,lt)
    prices = append(prices,price)
end for
 
function price_fix(atom p)
    for i=1 to length(limits) do
        if p<limits[i] then
            return prices[i]
        end if
    end for
    return -1
end function
 
for i=-1 to 101 do
    printf(1, "%5.2f %5.2f\n", {i/100,price_fix(i/100)})
end for

Phixmonti

include ..\Utilitys.pmt

(
( 0.00 0.06 0.10 )
( 0.06 0.11 0.18 )
( 0.11 0.16 0.26 )
( 0.16 0.21 0.32 )
( 0.21 0.26 0.38 )
( 0.26 0.31 0.44 )
( 0.31 0.36 0.50 )
( 0.36 0.41 0.54 )
( 0.41 0.46 0.58 )
( 0.46 0.51 0.62 )
( 0.51 0.56 0.66 )
( 0.56 0.61 0.70 )
( 0.61 0.66 0.74 )
( 0.66 0.71 0.78 )
( 0.71 0.76 0.82 )
( 0.76 0.81 0.86 )
( 0.81 0.86 0.90 )
( 0.86 0.91 0.94 )
( 0.91 0.96 0.98 )
( 0.96 1.01 1.00 ) )

def price_fix
    var p
    len for
        get
        3 get swap 1 get swap 2 get nip
        p swap < swap p swap >=
        and if
            exitfor
        else
            drop
        endif
    endfor
enddef

( 0.00 1.01 0.01 ) for
    dup print 9 tochar print price_fix print nl 
endfor

Picat

Approach 1

go =>
   _ = random2(),
   D = [
     [0.00,0.06,0.10],
     [0.06,0.11,0.18],
     [0.11,0.16,0.26],
     [0.16,0.21,0.32],
     [0.21,0.26,0.38],
     [0.26,0.31,0.44],
     [0.31,0.36,0.50],
     [0.36,0.41,0.54],
     [0.41,0.46,0.58],
     [0.46,0.51,0.62],
     [0.51,0.56,0.66],
     [0.56,0.61,0.70],
     [0.61,0.66,0.74],
     [0.66,0.71,0.78],
     [0.71,0.76,0.82],
     [0.76,0.81,0.86],
     [0.81,0.86,0.90],
     [0.86,0.91,0.94],
     [0.91,0.96,0.98],
     [0.96,1.01,1.00]],

  Len = D.length,
  foreach(_ in 1..10) 
    R = frand2(100),
    between(1,Len,Ix),
    R >= D[Ix,1],
    R < D[Ix,2],
    New = D[Ix,3],
    println(R=New)
  end,
  nl.

% Getting numbers of precision 2
frand2(N) = (random() mod N)/N.

Output:

0.2 = 0.32
0.91 = 0.98
0.44 = 0.58
0.81 = 0.9
0.74 = 0.82
0.1 = 0.18
0.42 = 0.58
0.93 = 0.98
0.14 = 0.26
0.62 = 0.74

Using a fact table

go2 =>
 _ = random2(),
  foreach(_ in 1..10) 
    R = frand2(100),
    r(From,To,Val),
    R >= From,
    R <= To,
    println(R=Val)
  end,

  nl.

r(0.00,0.06,0.10).
r(0.06,0.11,0.18).
r(0.11,0.16,0.26).
r(0.16,0.21,0.32).
r(0.21,0.26,0.38).
r(0.26,0.31,0.44).
r(0.31,0.36,0.50).
r(0.36,0.41,0.54).
r(0.41,0.46,0.58).
r(0.46,0.51,0.62).
r(0.51,0.56,0.66).
r(0.56,0.61,0.70).
r(0.61,0.66,0.74).
r(0.66,0.71,0.78).
r(0.71,0.76,0.82).
r(0.76,0.81,0.86).
r(0.81,0.86,0.90).
r(0.86,0.91,0.94).
r(0.91,0.96,0.98).
r(0.96,1.01,1.00).

Output:

0.83 = 0.9
0.77 = 0.86
0.65 = 0.74
0.08 = 0.18
0.08 = 0.18
0.02 = 0.1
0.73 = 0.82
0.99 = 1.0
0.58 = 0.7
0.0 = 0.1

PicoLisp

(scl 2)

(de price (Pr)
   (format
      (cdr
         (rank Pr
            (quote
               (0.00 . 0.10)
               (0.06 . 0.18)
               (0.11 . 0.26)
               (0.16 . 0.32)
               (0.21 . 0.38)
               (0.26 . 0.44)
               (0.31 . 0.50)
               (0.36 . 0.54)
               (0.41 . 0.58)
               (0.46 . 0.62)
               (0.51 . 0.66)
               (0.56 . 0.70)
               (0.61 . 0.74)
               (0.66 . 0.78)
               (0.71 . 0.82)
               (0.76 . 0.86)
               (0.81 . 0.90)
               (0.86 . 0.94)
               (0.91 . 0.98)
               (0.96 . 1.00) ) ) )
      *Scl ) )

(for N (0.3793 0.4425 0.0746 0.6918 0.2993 0.5486 0.7848 0.9383 0.2292)
   (prinl (price N)) )

Output:

0.54
0.58
0.18
0.78
0.44
0.66
0.86
0.98
0.38

PL/I

version 1

declare t(20) fixed decimal (3,2) static initial (
   .06, .11, .16, .21, .26, .31, .36, .41, .46,  .51,
   .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01);
declare r(20) fixed decimal (3,2) static initial (
   .10, .18, .26, .32, .38, .44, .50, .54, .58, .62,
   .66, .70, .74, .78, .82, .86, .90, .94, .98, 1);
declare x float, d fixed decimal (3,2);
declare i fixed binary;

loop:
   do i = 1 to 20;
      if x < t(i) then
         do; d = r(i); leave loop; end;
   end;

version 2

Translation of: REXX version2

cpt: Proc Options(main); 
 Dcl x Dec Fixed(4,2);
 Do x=0 To 1 By 0.01;
   Put Edit(x,' -> ',cp(x))(Skip,f(4,2),a,f(4,2));
   End;
 cp: Proc(p) Returns(Dec Fixed(4,2));
 Dcl r(20) Dec Fixed(4,2) static init(
   .10, .18, .26, .32, .38, .44, .50, .54, .58, .62,
   .66, .70, .74, .78, .82, .86, .90, .94, .98, 1);
 Dcl p Dec Fixed(4,2);
 Dcl i Bin Fixed;
 i=trunc((100*p-1)/5)+1;
 Return(r(i));
 End;
 End;

PowerShell

function Convert-PriceFraction
{
    [CmdletBinding()]
    [OutputType([double])]
    Param
    (
        [Parameter(Mandatory=$true,
                   ValueFromPipeline=$true,
                   ValueFromPipelineByPropertyName=$true,
                   Position=0)]
        [ValidateScript({$_ -ge 0.0 -and $_ -le 1.0})]
        [double]
        $InputObject
    )

    Process
    {
        foreach ($fraction in $InputObject)
        {
            switch ($fraction)
            {
                {$_ -lt 0.06} {0.10; break}
                {$_ -lt 0.11} {0.18; break}
                {$_ -lt 0.16} {0.26; break}
                {$_ -lt 0.21} {0.32; break}
                {$_ -lt 0.26} {0.38; break}
                {$_ -lt 0.31} {0.44; break}
                {$_ -lt 0.36} {0.50; break}
                {$_ -lt 0.41} {0.54; break}
                {$_ -lt 0.46} {0.58; break}
                {$_ -lt 0.51} {0.62; break}
                {$_ -lt 0.56} {0.66; break}
                {$_ -lt 0.61} {0.70; break}
                {$_ -lt 0.66} {0.74; break}
                {$_ -lt 0.71} {0.78; break}
                {$_ -lt 0.76} {0.82; break}
                {$_ -lt 0.81} {0.86; break}
                {$_ -lt 0.86} {0.90; break}
                {$_ -lt 0.91} {0.94; break}
                {$_ -lt 0.96} {0.98; break}
                Default       {1.00}
            }
        }
    }
}

.7388727, .8593103, .826687, .3444635, .0491907 | Convert-PriceFraction | ForEach-Object {"{0:C}" -f $_}

Output:

$0.82
$0.90
$0.90
$0.50
$0.10

Python

Using the bisect standard module to reduce the comparisons with members of the cin array.

>>> import bisect
>>> _cin  = [.06, .11, .16, .21, .26, .31, .36, .41, .46, .51, .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01]
>>> _cout = [.10, .18, .26, .32, .38, .44, .50, .54, .58, .62, .66, .70, .74, .78, .82, .86, .90, .94, .98, 1.00]
>>> def pricerounder(pricein):
	return _cout[ bisect.bisect_right(_cin, pricein) ]

When dealing with money it is good to think about possible loss of precision. If we change the units to be integer cents we could use the following exact routine:

>>> import bisect
>>> _cin  = [ 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96, 101]
>>> _cout = [10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100]
>>> def centsrounder(centsin):
	return _cout[ bisect.bisect_right(_cin, centsin) ]

Other options are to use the fractions or decimals modules for calculating money to a known precision.

Bisection library code

The bisect Python standard library function uses the following code that improves on a simple linear scan through a sorted list:

def bisect_right(a, x, lo=0, hi=None):
    """Return the index where to insert item x in list a, assuming a is sorted.

    The return value i is such that all e in a[:i] have e <= x, and all e in
    a[i:] have e > x.  So if x already appears in the list, a.insert(x) will
    insert just after the rightmost x already there.

    Optional args lo (default 0) and hi (default len(a)) bound the
    slice of a to be searched.
    """

    if lo < 0:
        raise ValueError('lo must be non-negative')
    if hi is None:
        hi = len(a)
    while lo < hi:
        mid = (lo+hi)//2
        if x < a[mid]: hi = mid
        else: lo = mid+1
    return lo

Quackery

This program uses the bignum rationals provided by bigrat.qky, so it avoids the pitfalls of storing money as floating point numbers.

[ $ 'bigrat.qky' loadfile ] now!

[ 2over 2over v< if 2swap 2drop ] is vmax  ( n/d n/d --> n/d )

[ 100 1 v* 1 1 v-
  0 1 vmax 5 1 v/ /
  [ table
    10 18 26 32 38
    44 50 54 58 62
    66 70 74 78 82
    86 90 94 98 100 ] 100 ]       is scale ( n/d     --> n/d )

[ swap echo sp echo ]             is br    ( n/d     -->     )

[ 2dup br say ' --> '
  scale br cr ]                   is test  ( n/d     -->     )

0 100 test
50 100 test
65 100 test
66 100 test
100 100 test
7368 10000 test

( Show how to enter and display results as a decimal too. )
$ '0.7368' dup echo$
say ' --> '
$->v drop scale
2 point$ echo$

Output:

0 100 --> 10 100
50 100 --> 62 100
65 100 --> 74 100
66 100 --> 78 100
100 100 --> 100 100
7368 10000 --> 82 100
0.7368 --> 0.82

R

price_fraction <- function(x)
{
  stopifnot(all(x >= 0 & x <= 1))
  breaks <- seq(0.06, 1.01, 0.05)
  values <- c(.1, .18, .26, .32, .38, .44, .5, .54, .58, .62, .66, .7, .74, .78, .82, .86, .9, .94, .98, 1)
  indices <- sapply(x, function(x) which(x < breaks)[1])
  values[indices]
}

#Example usage:
price_fraction(c(0, .01, 0.06, 0.25, 1))                # 0.10 0.10 0.18 0.38 1.00

You can extract the contents of the table as follows:

dfr <- read.table(tc <- textConnection(
">=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00")); close(tc)
breaks <- dfr$V4
values <- dfr$V6

Racket

#lang racket

(define table
  '([0 #f]
    [0.06 0.10] [0.11 0.18] [0.16 0.26] [0.21 0.32] [0.26 0.38] [0.31 0.44]
    [0.36 0.50] [0.41 0.54] [0.46 0.58] [0.51 0.62] [0.56 0.66] [0.61 0.70]
    [0.66 0.74] [0.71 0.78] [0.76 0.82] [0.81 0.86] [0.86 0.90] [0.91 0.94]
    [0.96 0.98] [1.01 1.00])

  ;; returns #f for negatives or values >= 1.01
(define (convert x) (for/or ([c table]) (and (< x (car c)) (cadr c))))

Raku

(formerly Perl 6)

Simple solution, doing a linear search.
Note that in Raku we don't have to worry about floating-point misrepresentations of decimals, because decimal fractions are stored as rationals.

Works with: rakudo version 2016.07

sub price-fraction ($n where 0..1) {
    when $n < 0.06 { 0.10 }
    when $n < 0.11 { 0.18 }
    when $n < 0.16 { 0.26 }
    when $n < 0.21 { 0.32 }
    when $n < 0.26 { 0.38 }
    when $n < 0.31 { 0.44 }
    when $n < 0.36 { 0.50 }
    when $n < 0.41 { 0.54 }
    when $n < 0.46 { 0.58 }
    when $n < 0.51 { 0.62 }
    when $n < 0.56 { 0.66 }
    when $n < 0.61 { 0.70 }
    when $n < 0.66 { 0.74 }
    when $n < 0.71 { 0.78 }
    when $n < 0.76 { 0.82 }
    when $n < 0.81 { 0.86 }
    when $n < 0.86 { 0.90 }
    when $n < 0.91 { 0.94 }
    when $n < 0.96 { 0.98 }
    default        { 1.00 }
}

while prompt("value: ") -> $value {
    say price-fraction(+$value);
}

If we expect to rescale many prices, a better approach would be to build a look-up array of 101 entries. Memory is cheap, and array indexing is blazing fast.

my @price = map *.value, flat
    ( 0 ..^ 6  X=> 0.10),
    ( 6 ..^ 11 X=> 0.18),
    (11 ..^ 16 X=> 0.26),
    (16 ..^ 21 X=> 0.32),
    (21 ..^ 26 X=> 0.38),
    (26 ..^ 31 X=> 0.44),
    (31 ..^ 36 X=> 0.50),
    (36 ..^ 41 X=> 0.54),
    (41 ..^ 46 X=> 0.58),
    (46 ..^ 51 X=> 0.62),
    (51 ..^ 56 X=> 0.66),
    (56 ..^ 61 X=> 0.70),
    (61 ..^ 66 X=> 0.74),
    (66 ..^ 71 X=> 0.78),
    (71 ..^ 76 X=> 0.82),
    (76 ..^ 81 X=> 0.86),
    (81 ..^ 86 X=> 0.90),
    (86 ..^ 91 X=> 0.94),
    (91 ..^ 96 X=> 0.98),
    (96 ..^101 X=> 1.00),
;

while prompt("value: ") -> $value {
    say @price[$value * 100] // "Out of range";
}

We can also build this same look-up array by parsing the table as formatted in the task description:

Works with: rakudo version 2016.07

my $table = q:to/END/;
>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00
END

my @price;

for $table.lines {
    /:s '>='  (\S+)  '<'  (\S+)  ':='  (\S+)/;
    @price[$0*100 ..^ $1*100] »=» +$2;
}

while prompt("value: ") -> $value {
    say @price[$value * 100] // "Out of range";
}

Raven

Translation of: JavaScript

define getScaleFactor use $v
   [ 0.1 0.18 0.26 0.32 0.38 0.44 0.50 0.54 0.58 0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90 0.94 0.98 1.0 ] as $vals
   $v 100 * 1 - 5 /    20 min  0 max  1 prefer dup $v "val: %g  indx: %d\n" print   $vals swap get

0 100 9 range each
    100.0 / dup getScaleFactor swap "%.2g -> %.2g\n" print

Output:

0 -> 0.1
0.09 -> 0.18
0.18 -> 0.32
0.27 -> 0.44
0.36 -> 0.54
0.45 -> 0.58
0.54 -> 0.66
0.63 -> 0.74
0.72 -> 0.82
0.81 -> 0.9
0.9 -> 0.94
0.99 -> 1

REXX

version 1

/*REXX program re─scales a (decimal fraction)  price  (in the range of:   0¢  ──►  $1). */
pad= '     '                                     /*for inserting spaces into a message. */
          do j=0  to 1  by .01                   /*process the prices from 0¢  to  ≤ $1 */
          if j==0  then j= 0.00                  /*handle the special case of zero cents*/
          say pad  'original price ──►'    j   pad   adjPrice(j)     " ◄── adjusted price"
          end   /*j*/
exit 0                                           /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
adjPrice: procedure;  parse arg ?                /*a table is used to facilitate changes*/
                                     select
                                     when ?<0.06  then ?= 0.10
                                     when ?<0.11  then ?= 0.18
                                     when ?<0.16  then ?= 0.26
                                     when ?<0.21  then ?= 0.32
                                     when ?<0.26  then ?= 0.38
                                     when ?<0.31  then ?= 0.44
                                     when ?<0.36  then ?= 0.50
                                     when ?<0.41  then ?= 0.54
                                     when ?<0.46  then ?= 0.58
                                     when ?<0.51  then ?= 0.62
                                     when ?<0.56  then ?= 0.66
                                     when ?<0.61  then ?= 0.70
                                     when ?<0.66  then ?= 0.74
                                     when ?<0.71  then ?= 0.78
                                     when ?<0.76  then ?= 0.82
                                     when ?<0.81  then ?= 0.86
                                     when ?<0.86  then ?= 0.90
                                     when ?<0.91  then ?= 0.94
                                     when ?<0.96  then ?= 0.98
                                     when ?<1.01  then ?= 1.00
                                     otherwise    nop
                                     end   /*select*/
          return ?

output :

      original price ──► 0.00       0.10  ◄── adjusted price
      original price ──► 0.01       0.10  ◄── adjusted price
      original price ──► 0.02       0.10  ◄── adjusted price
      original price ──► 0.03       0.10  ◄── adjusted price
      original price ──► 0.04       0.10  ◄── adjusted price
      original price ──► 0.05       0.10  ◄── adjusted price
      original price ──► 0.06       0.18  ◄── adjusted price
      original price ──► 0.07       0.18  ◄── adjusted price
      original price ──► 0.08       0.18  ◄── adjusted price
      original price ──► 0.09       0.18  ◄── adjusted price
      original price ──► 0.10       0.18  ◄── adjusted price
      original price ──► 0.11       0.26  ◄── adjusted price
      original price ──► 0.12       0.26  ◄── adjusted price
      original price ──► 0.13       0.26  ◄── adjusted price
      original price ──► 0.14       0.26  ◄── adjusted price
      original price ──► 0.15       0.26  ◄── adjusted price
      original price ──► 0.16       0.32  ◄── adjusted price
      original price ──► 0.17       0.32  ◄── adjusted price
      original price ──► 0.18       0.32  ◄── adjusted price
      original price ──► 0.19       0.32  ◄── adjusted price
      original price ──► 0.20       0.32  ◄── adjusted price
      original price ──► 0.21       0.38  ◄── adjusted price
      original price ──► 0.22       0.38  ◄── adjusted price
      original price ──► 0.23       0.38  ◄── adjusted price
      original price ──► 0.24       0.38  ◄── adjusted price
      original price ──► 0.25       0.38  ◄── adjusted price
      original price ──► 0.26       0.44  ◄── adjusted price
      original price ──► 0.27       0.44  ◄── adjusted price
      original price ──► 0.28       0.44  ◄── adjusted price
      original price ──► 0.29       0.44  ◄── adjusted price
      original price ──► 0.30       0.44  ◄── adjusted price
      original price ──► 0.31       0.50  ◄── adjusted price
      original price ──► 0.32       0.50  ◄── adjusted price
      original price ──► 0.33       0.50  ◄── adjusted price
      original price ──► 0.34       0.50  ◄── adjusted price
      original price ──► 0.35       0.50  ◄── adjusted price
      original price ──► 0.36       0.54  ◄── adjusted price
      original price ──► 0.37       0.54  ◄── adjusted price
      original price ──► 0.38       0.54  ◄── adjusted price
      original price ──► 0.39       0.54  ◄── adjusted price
      original price ──► 0.40       0.54  ◄── adjusted price
      original price ──► 0.41       0.58  ◄── adjusted price
      original price ──► 0.42       0.58  ◄── adjusted price
      original price ──► 0.43       0.58  ◄── adjusted price
      original price ──► 0.44       0.58  ◄── adjusted price
      original price ──► 0.45       0.58  ◄── adjusted price
      original price ──► 0.46       0.62  ◄── adjusted price
      original price ──► 0.47       0.62  ◄── adjusted price
      original price ──► 0.48       0.62  ◄── adjusted price
      original price ──► 0.49       0.62  ◄── adjusted price
      original price ──► 0.50       0.62  ◄── adjusted price
      original price ──► 0.51       0.66  ◄── adjusted price
      original price ──► 0.52       0.66  ◄── adjusted price
      original price ──► 0.53       0.66  ◄── adjusted price
      original price ──► 0.54       0.66  ◄── adjusted price
      original price ──► 0.55       0.66  ◄── adjusted price
      original price ──► 0.56       0.70  ◄── adjusted price
      original price ──► 0.57       0.70  ◄── adjusted price
      original price ──► 0.58       0.70  ◄── adjusted price
      original price ──► 0.59       0.70  ◄── adjusted price
      original price ──► 0.60       0.70  ◄── adjusted price
      original price ──► 0.61       0.74  ◄── adjusted price
      original price ──► 0.62       0.74  ◄── adjusted price
      original price ──► 0.63       0.74  ◄── adjusted price
      original price ──► 0.64       0.74  ◄── adjusted price
      original price ──► 0.65       0.74  ◄── adjusted price
      original price ──► 0.66       0.78  ◄── adjusted price
      original price ──► 0.67       0.78  ◄── adjusted price
      original price ──► 0.68       0.78  ◄── adjusted price
      original price ──► 0.69       0.78  ◄── adjusted price
      original price ──► 0.70       0.78  ◄── adjusted price
      original price ──► 0.71       0.82  ◄── adjusted price
      original price ──► 0.72       0.82  ◄── adjusted price
      original price ──► 0.73       0.82  ◄── adjusted price
      original price ──► 0.74       0.82  ◄── adjusted price
      original price ──► 0.75       0.82  ◄── adjusted price
      original price ──► 0.76       0.86  ◄── adjusted price
      original price ──► 0.77       0.86  ◄── adjusted price
      original price ──► 0.78       0.86  ◄── adjusted price
      original price ──► 0.79       0.86  ◄── adjusted price
      original price ──► 0.80       0.86  ◄── adjusted price
      original price ──► 0.81       0.90  ◄── adjusted price
      original price ──► 0.82       0.90  ◄── adjusted price
      original price ──► 0.83       0.90  ◄── adjusted price
      original price ──► 0.84       0.90  ◄── adjusted price
      original price ──► 0.85       0.90  ◄── adjusted price
      original price ──► 0.86       0.94  ◄── adjusted price
      original price ──► 0.87       0.94  ◄── adjusted price
      original price ──► 0.88       0.94  ◄── adjusted price
      original price ──► 0.89       0.94  ◄── adjusted price
      original price ──► 0.90       0.94  ◄── adjusted price
      original price ──► 0.91       0.98  ◄── adjusted price
      original price ──► 0.92       0.98  ◄── adjusted price
      original price ──► 0.93       0.98  ◄── adjusted price
      original price ──► 0.94       0.98  ◄── adjusted price
      original price ──► 0.95       0.98  ◄── adjusted price
      original price ──► 0.96       1.00  ◄── adjusted price
      original price ──► 0.97       1.00  ◄── adjusted price
      original price ──► 0.98       1.00  ◄── adjusted price
      original price ──► 0.99       1.00  ◄── adjusted price
      original price ──► 1.00       1.00  ◄── adjusted price

version 2

/* REXX ***************************************************************
* Inspired by some other solutions tested with version 1 (above)
* 20.04.2013 Walter Pachl
* 03.11.2013 -"- move r. computation (once is enough)
**********************************************************************/
rl='0.10 0.18 0.26 0.32 0.38 0.44 0.50 0.54 0.58 0.62',
   '0.66 0.70 0.74 0.78 0.82 0.86 0.90 0.94 0.98 1.00'
Do i=1 To 20
  Parse Var rl r.i rl
  End
Do x=0 To 1 By 0.01
  old=adjprice(x)
  new=adjprice2(x)
  If old<>new Then tag='??'
  else tag=''
  Say x old new  tag
  End
Exit

adjprice2: Procedure Expose r.
  i=((100*arg(1)-1)%5+1)
  Return r.i

Ring

see pricefraction(0.5)
 
func pricefraction n
     if n < 0.06 return 0.10 ok
     if n < 0.11 return 0.18 ok
     if n < 0.16 return 0.26 ok
     if n < 0.21 return 0.32 ok
     if n < 0.26 return 0.38 ok
     if n < 0.31 return 0.44 ok
     if n < 0.36 return 0.50 ok
     if n < 0.41 return 0.54 ok
     if n < 0.46 return 0.58 ok
     if n < 0.51 return 0.62 ok
     if n < 0.56 return 0.66 ok
     if n < 0.61 return 0.70 ok
     if n < 0.66 return 0.74 ok
     if n < 0.71 return 0.78 ok
     if n < 0.76 return 0.82 ok
     if n < 0.81 return 0.86 ok
     if n < 0.86 return 0.90 ok
     if n < 0.91 return 0.94 ok 
     if n < 0.96 return 0.98 ok
     return 1

RPL

Works with: Halcyon Calc version 4.2.7

RPL code

Comment

≪ → input 
   ≪ { 0.10 0.18 0.26 0.32 0.38 0.44 0.50 
        0.54 0.58 0.62 0.66 0.70 0.74 0.78 
        0.82 0.86 0.90 0.94 0.98 1 }
      { 0.06 0.11 0.16 0.21 0.26 0.31 0.36 
        0.41 0.46 0.51 0.56 0.61 0.66 0.71 
        0.76 0.81 0.86 0.91 0.96 1.01 }
      1 WHILE GETI input < REPEAT END
      IF DUP 1 == THEN DROP DUP SIZE ELSE 1 - END
      SWAP DROP GET 2 FIX
≫ ≫ 'PRICE' STO

PRICE ( gross -- net ) 
list of net values
.
.
list of thresholds
.
.
scan thresholds until passed
1 step down
forget thresholds and get net value with 2 decimals
.

Input:

0 PRICE 
0.25 PRICE
0.5 PRICE
0.75 PRICE
1 PRICE

Output:

5: 0.10
4: 0.38
3: 0.62
2: 0.82
1: 1.00

Ruby

A simple function with hardcoded values.

def rescale_price_fraction(value)
  raise ArgumentError, "value=#{value}, must have: 0 <= value < 1.01" if value < 0 || value >= 1.01
  if     value < 0.06  then  0.10
  elsif  value < 0.11  then  0.18
  elsif  value < 0.16  then  0.26
  elsif  value < 0.21  then  0.32
  elsif  value < 0.26  then  0.38
  elsif  value < 0.31  then  0.44
  elsif  value < 0.36  then  0.50
  elsif  value < 0.41  then  0.54
  elsif  value < 0.46  then  0.58
  elsif  value < 0.51  then  0.62
  elsif  value < 0.56  then  0.66
  elsif  value < 0.61  then  0.70
  elsif  value < 0.66  then  0.74
  elsif  value < 0.71  then  0.78
  elsif  value < 0.76  then  0.82
  elsif  value < 0.81  then  0.86
  elsif  value < 0.86  then  0.90
  elsif  value < 0.91  then  0.94
  elsif  value < 0.96  then  0.98
  elsif  value < 1.01  then  1.00
  end
end

Or, where we can cut and paste the textual table in one place

Works with: Ruby version 1.8.7+

for the String#lines method.

For Ruby 1.8.6, use String#each_line

class Price
  ConversionTable = <<-END_OF_TABLE
    >=  0.00  <  0.06  :=  0.10
    >=  0.06  <  0.11  :=  0.18
    >=  0.11  <  0.16  :=  0.26
    >=  0.16  <  0.21  :=  0.32
    >=  0.21  <  0.26  :=  0.38
    >=  0.26  <  0.31  :=  0.44
    >=  0.31  <  0.36  :=  0.50
    >=  0.36  <  0.41  :=  0.54
    >=  0.41  <  0.46  :=  0.58
    >=  0.46  <  0.51  :=  0.62
    >=  0.51  <  0.56  :=  0.66
    >=  0.56  <  0.61  :=  0.70
    >=  0.61  <  0.66  :=  0.74
    >=  0.66  <  0.71  :=  0.78
    >=  0.71  <  0.76  :=  0.82
    >=  0.76  <  0.81  :=  0.86
    >=  0.81  <  0.86  :=  0.90
    >=  0.86  <  0.91  :=  0.94
    >=  0.91  <  0.96  :=  0.98
    >=  0.96  <  1.01  :=  1.00
  END_OF_TABLE

  RE = %r{ ([<>=]+) \s* (\d\.\d\d) \s* ([<>=]+) \s* (\d\.\d\d) \D+ (\d\.\d\d) }x

  # extract the comparison operators and numbers from the table
  CONVERSION_TABLE = ConversionTable.lines.inject([]) do |table, line| 
    m = line.match(RE) 
    if not m.nil? and m.length == 6
      table << [m[1], m[2].to_f, m[3], m[4].to_f, m[5].to_f] 
    end
    table
  end

  MIN_COMP, MIN = CONVERSION_TABLE[0][0..1] 
  MAX_COMP, MAX = CONVERSION_TABLE[-1][2..3]

  def initialize(value)
    if (not value.send(MIN_COMP, MIN)) or (not value.send(MAX_COMP, MAX))
      raise ArgumentError, "value=#{value}, must have: #{MIN} #{MIN_COMP} value #{MAX_COMP} #{MAX}"
    end
    @standard_value = CONVERSION_TABLE.find do |comp1, lower, comp2, upper, standard|
      value.send(comp1, lower) and value.send(comp2, upper)
    end.last
  end
  attr_reader :standard_value
end

And a test suite

require 'test/unit'

class PriceFractionTests < Test::Unit::TestCase
  @@ok_tests = [
    [0.3793, 0.54],
    [0.4425, 0.58],
    [0.0746, 0.18],
    [0.6918, 0.78],
    [0.2993, 0.44],
    [0.5486, 0.66],
    [0.7848, 0.86],
    [0.9383, 0.98],
    [0.2292, 0.38],
  ]
  @@bad_tests = [1.02, -3]

  def test_ok
    @@ok_tests.each do |val, exp| 
      assert_equal(exp, rescale_price_fraction(val))
      assert_equal(exp, Price.new(val).standard_value)
    end
    @@bad_tests.each do |val| 
      assert_raise(ArgumentError) {rescale_price_fraction(val)}
      assert_raise(ArgumentError) {Price.new(val).standard_value}
    end
  end
end

Output:

Loaded suite price_fraction
Started
.
Finished in 0.001000 seconds.

1 tests, 22 assertions, 0 failures, 0 errors, 0 skips

Another option is using a built-in binary search:

keys   = [ 0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01]
prices = [0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00]

tests = [0.3793, 0.4425, 0.0746, 0.6918, 0.2993, 0.5486, 0.7849, 0.9383, 0.2292]
tests.each do |test|
  price = prices[ keys.bsearch_index{|key| key >= test } ]
  puts [test, price].join(": ") 
end

Rust

fn fix_price(num: f64) -> f64 {
    match num {
        0.96...1.00 => 1.00,
        0.91...0.96 => 0.98,
        0.86...0.91 => 0.94,
        0.81...0.86 => 0.90,
        0.76...0.81 => 0.86,
        0.71...0.76 => 0.82,
        0.66...0.71 => 0.78,
        0.61...0.66 => 0.74,
        0.56...0.61 => 0.70,
        0.51...0.56 => 0.66,
        0.46...0.51 => 0.62,
        0.41...0.46 => 0.58,
        0.36...0.41 => 0.54,
        0.31...0.36 => 0.50,
        0.26...0.31 => 0.44,
        0.21...0.26 => 0.38,
        0.16...0.21 => 0.32,
        0.11...0.16 => 0.26,
        0.06...0.11 => 0.18,
        0.00...0.06 => 0.10,
        // panics on invalid value
        _ => unreachable!(),
    }
}

fn main() {
    let mut n: f64 = 0.04;
    while n <= 1.00 {
        println!("{:.2} => {}", n, fix_price(n));
        n += 0.04;
    }
}

// and a unit test to check that we haven't forgotten a branch, use 'cargo test' to execute test.
//
// typically this could be included in the match as those check for exhaustiveness already
// by explicitly listing all remaining ranges / values instead of a catch-all underscore (_)
// but f64::NaN, f64::INFINITY and f64::NEG_INFINITY can't be matched like this
#[test]
fn exhaustiveness_check() {
    let mut input_price = 0.;
    while input_price <= 1. {
        fix_price(input_price);
        input_price += 0.01;
    }
}

Output:

0.04 => 0.1
0.09 => 0.18
0.14 => 0.26
0.19 => 0.32
0.24 => 0.38
0.29 => 0.44
0.34 => 0.5
0.39 => 0.54
0.44 => 0.58
0.49 => 0.62
0.54 => 0.66
0.59 => 0.7
0.64 => 0.74
0.69 => 0.78
0.74 => 0.82
0.79 => 0.86
0.84 => 0.9
0.89 => 0.94
0.94 => 0.98
0.99 => 1

Output of unit test:

running 1 test
test exhaustiveness_check ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured

Scala

def priceFraction(x:Double)=x match {
   case n if n>=0 && n<0.06 => 0.10
   case n if n<0.11 => 0.18
   case n if n<0.36 => ((((n*100).toInt-11)/5)*6+26)/100.toDouble
   case n if n<0.96 => ((((n*100).toInt-31)/5)*4+50)/100.toDouble
   case _ => 1.00
}

def testPriceFraction()=
   for(n <- 0.00 to (1.00, 0.01)) println("%.2f  %.2f".format(n, priceFraction(n)))

Output:

Seed7

$ include "seed7_05.s7i";
  include "float.s7i";

const func float: computePrice (in float: x) is func
  result
    var float: price is 0.0;
  begin
    if x >= 0.0 and x < 0.06 then
      price := 0.10;
    elsif x < 0.11 then
      price := 0.18;
    elsif x < 0.36 then
      price := flt(((trunc(x * 100.0) - 11) div 5) * 6 + 26) / 100.0;
    elsif x < 0.96 then
      price := flt(((trunc(x * 100.0) - 31) div 5) * 4 + 50) / 100.0;
    else
      price := 1.0;
    end if;
  end func;

const proc: main is func
  local
    var integer: i is 0;
  begin
    for i range 0 to 100 do
      writeln(flt(i) / 100.0 digits 2 <& " " <& computePrice(flt(i) / 100.0) digits 2);
    end for;
  end func;

The following variant of computePrice works with a table and raises RANGE_ERROR when x < 0.0 or x >= 1.01 holds:

const array array float: table is [] (
    [] (0.06, 0.10), [] (0.11, 0.18), [] (0.16, 0.26), [] (0.21, 0.32), [] (0.26, 0.38),
    [] (0.31, 0.44), [] (0.36, 0.50), [] (0.41, 0.54), [] (0.46, 0.58), [] (0.51, 0.62),
    [] (0.56, 0.66), [] (0.61, 0.70), [] (0.66, 0.74), [] (0.71, 0.78), [] (0.76, 0.82),
    [] (0.81, 0.86), [] (0.86, 0.90), [] (0.91, 0.94), [] (0.96, 0.98), [] (1.01, 1.00));

const func float: computePrice (in float: x) is func
  result
    var float: price is 0.0;
  local
    var integer: index is 1;
  begin
    if x >= 0.0 then
      while x >= table[index][1] do
        incr(index);
      end while;
      price := table[index][2];
    else
      raise RANGE_ERROR;
    end if;
  end func;

Sidef

var table = <<'EOT'.lines.map { .words.grep{.is_numeric}.map{.to_n} }
>=  0.00  <  0.06  :=  0.10
>=  0.06  <  0.11  :=  0.18
>=  0.11  <  0.16  :=  0.26
>=  0.16  <  0.21  :=  0.32
>=  0.21  <  0.26  :=  0.38
>=  0.26  <  0.31  :=  0.44
>=  0.31  <  0.36  :=  0.50
>=  0.36  <  0.41  :=  0.54
>=  0.41  <  0.46  :=  0.58
>=  0.46  <  0.51  :=  0.62
>=  0.51  <  0.56  :=  0.66
>=  0.56  <  0.61  :=  0.70
>=  0.61  <  0.66  :=  0.74
>=  0.66  <  0.71  :=  0.78
>=  0.71  <  0.76  :=  0.82
>=  0.76  <  0.81  :=  0.86
>=  0.81  <  0.86  :=  0.90
>=  0.86  <  0.91  :=  0.94
>=  0.91  <  0.96  :=  0.98
>=  0.96  <  1.01  :=  1.00
EOT

func price(money) {
    table.each { |row|
           (row[0] <= money) ->
        && (row[1] >  money) ->
        && return row[2];
    }
    die "Out of range";
}

for n in %n(0.3793 0.4425 0.0746 0.6918 0.2993 0.5486 0.7848 0.9383 0.2292) {
    say price(n);
}

Output:

0.54
0.58
0.18
0.78
0.44
0.66
0.86
0.98
0.38

Smalltalk

Works with: GNU Smalltalk

"Table driven rescale"
Object subclass: PriceRescale [
  |table|
  PriceRescale class  >> new: theTable [
    ^ self basicNew initialize: theTable
  ]
  initialize: theTable [
     table := theTable asOrderedCollection.
     ^self
  ]
  rescale: aPrice [ |v1 v2|
    1 to: (table size - 1) do: [:i|
      v1 := table at: i.
      v2 := table at: (i+1).
      ((aPrice >= (v1 x)) & (aPrice < (v2 x)))
        ifTrue: [ ^ v1 y ]
    ].
    (aPrice < ((v1:=(table first)) x)) ifTrue: [ ^ v1 y ]. 
    (aPrice >= ((v1:=(table last)) x)) ifTrue: [ ^ v1 y ]
  ]
].

|pr|
pr := PriceRescale 
         new: {  0.00@0.10 .
                 0.06@0.18 .
                 0.11@0.26 .
                 0.16@0.32 .
                 0.21@0.38 .
                 0.26@0.44 .
                 0.31@0.50 .
                 0.36@0.54 .
                 0.41@0.58 .
                 0.46@0.62 .
                 0.51@0.66 .
                 0.56@0.70 .
                 0.61@0.74 .
                 0.66@0.78 .
                 0.71@0.82 .
                 0.76@0.86 .
                 0.81@0.90 .
                 0.86@0.94 .
                 0.91@0.98 .
                 0.96@1.00 .
                 1.01@1.00
               }.

"get a price"
(pr rescale: ( (Random between: 0 and: 100)/100 )) displayNl.

Swift

let ranges = [
  (0.00..<0.06, 0.10),
  (0.06..<0.11, 0.18),
  (0.11..<0.16, 0.26),
  (0.16..<0.21, 0.32),
  (0.21..<0.26, 0.38),
  (0.26..<0.31, 0.44),
  (0.31..<0.36, 0.50),
  (0.36..<0.41, 0.54),
  (0.41..<0.46, 0.58),
  (0.46..<0.51, 0.62),
  (0.51..<0.56, 0.66),
  (0.56..<0.61, 0.70),
  (0.61..<0.66, 0.74),
  (0.66..<0.71, 0.78),
  (0.71..<0.76, 0.82),
  (0.76..<0.81, 0.86),
  (0.81..<0.86, 0.90),
  (0.86..<0.91, 0.94),
  (0.91..<0.96, 0.98),
  (0.96..<1.01, 1.00)
]

func adjustDouble(_ val: Double, accordingTo ranges: [(Range<Double>, Double)]) -> Double? {
  return ranges.first(where: { $0.0.contains(val) })?.1
}

for val in stride(from: 0.0, through: 1, by: 0.01) {
  let strFmt = { String(format: "%.2f", $0) }

  print("\(strFmt(val)) -> \(strFmt(adjustDouble(val, accordingTo: ranges) ?? val))")
}

Output:

0.00 -> 0.10
0.01 -> 0.10
0.02 -> 0.10
0.03 -> 0.10
0.04 -> 0.10
0.05 -> 0.10
0.06 -> 0.18
0.07 -> 0.18
0.08 -> 0.18
0.09 -> 0.18
0.10 -> 0.18
0.11 -> 0.26
0.12 -> 0.26
0.13 -> 0.26
0.14 -> 0.26
0.15 -> 0.26
0.16 -> 0.32
0.17 -> 0.32
0.18 -> 0.32
0.19 -> 0.32
0.20 -> 0.32
0.21 -> 0.38
0.22 -> 0.38
0.23 -> 0.38
0.24 -> 0.38
0.25 -> 0.38
0.26 -> 0.44
0.27 -> 0.44
0.28 -> 0.44
0.29 -> 0.44
0.30 -> 0.44
0.31 -> 0.50
0.32 -> 0.50
0.33 -> 0.50
0.34 -> 0.50
0.35 -> 0.50
0.36 -> 0.54
0.37 -> 0.54
0.38 -> 0.54
0.39 -> 0.54
0.40 -> 0.54
0.41 -> 0.58
0.42 -> 0.58
0.43 -> 0.58
0.44 -> 0.58
0.45 -> 0.58
0.46 -> 0.62
0.47 -> 0.62
0.48 -> 0.62
0.49 -> 0.62
0.50 -> 0.62
0.51 -> 0.66
0.52 -> 0.66
0.53 -> 0.66
0.54 -> 0.66
0.55 -> 0.66
0.56 -> 0.70
0.57 -> 0.70
0.58 -> 0.70
0.59 -> 0.70
0.60 -> 0.70
0.61 -> 0.74
0.62 -> 0.74
0.63 -> 0.74
0.64 -> 0.74
0.65 -> 0.74
0.66 -> 0.78
0.67 -> 0.78
0.68 -> 0.78
0.69 -> 0.78
0.70 -> 0.78
0.71 -> 0.82
0.72 -> 0.82
0.73 -> 0.82
0.74 -> 0.82
0.75 -> 0.82
0.76 -> 0.86
0.77 -> 0.86
0.78 -> 0.86
0.79 -> 0.86
0.80 -> 0.86
0.81 -> 0.90
0.82 -> 0.90
0.83 -> 0.90
0.84 -> 0.90
0.85 -> 0.90
0.86 -> 0.94
0.87 -> 0.94
0.88 -> 0.94
0.89 -> 0.94
0.90 -> 0.94
0.91 -> 0.98
0.92 -> 0.98
0.93 -> 0.98
0.94 -> 0.98
0.95 -> 0.98
0.96 -> 1.00
0.97 -> 1.00
0.98 -> 1.00
0.99 -> 1.00
1.00 -> 1.00

Tcl

Structured as two functions, one to parse the input data as described in the problem into a form which Tcl can work with easily, and the other to perform the mapping.

# Used once to turn the table into a "nice" form
proc parseTable table {
    set map {}
    set LINE_RE {^ *>= *([0-9.]+) *< *([0-9.]+) *:= *([0-9.]+) *$}
    foreach line [split $table \n] {
	if {[string trim $line] eq ""} continue
	if {[regexp $LINE_RE $line -> min max target]} {
	    lappend map $min $max $target
	} else {
	    error "invalid table format: $line"
	}
    }
    return $map
}

# How to apply the "nice" table to a particular value
proc priceFraction {map value} {
    foreach {minimum maximum target} $map {
	if {$value >= $minimum && $value < $maximum} {return $target}
    }
    # Failed to map; return the input
    return $value
}

How it is used:

# Make the mapping
set inputTable {
    >=  0.00  <  0.06  :=  0.10
    >=  0.06  <  0.11  :=  0.18
    >=  0.11  <  0.16  :=  0.26
    >=  0.16  <  0.21  :=  0.32
    >=  0.21  <  0.26  :=  0.38
    >=  0.26  <  0.31  :=  0.44
    >=  0.31  <  0.36  :=  0.50
    >=  0.36  <  0.41  :=  0.54
    >=  0.41  <  0.46  :=  0.58
    >=  0.46  <  0.51  :=  0.62
    >=  0.51  <  0.56  :=  0.66
    >=  0.56  <  0.61  :=  0.70
    >=  0.61  <  0.66  :=  0.74
    >=  0.66  <  0.71  :=  0.78
    >=  0.71  <  0.76  :=  0.82
    >=  0.76  <  0.81  :=  0.86
    >=  0.81  <  0.86  :=  0.90
    >=  0.86  <  0.91  :=  0.94
    >=  0.91  <  0.96  :=  0.98
    >=  0.96  <  1.01  :=  1.00
}
set map [parseTable $inputTable]

# Apply the mapping to some inputs (from the Oz example)
foreach example {.7388727 .8593103 .826687 .3444635 .0491907} {
    puts "$example -> [priceFraction $map $example]"
}

Output:

.7388727 -> 0.82
.8593103 -> 0.90
.826687 -> 0.90
.3444635 -> 0.50
.0491907 -> 0.10

Ursala

#import flo                     

le  = <0.06,.11,.16,.21,.26,.31,.36,.41,.46,.51,.56,.61,.66,.71,.76,.81,.86,.91,.96,1.01>
out = <0.10,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.90,.94,.98,1.>

price_fraction = fleq@rlPlX*|rhr\~&p(le,out)

main points:

~&p(le,out) zips the pair of lists le and out into a list of pairs
A function of the form f\y applied to an argument x evaluates to f(x,y)
A function of the form f*| applied to a pair (x,y) where y is a list, makes a list of pairs with x on the left of each item and an item of y on the right. Then it applies f to each pair, makes a list of the right sides of those for which f returned true, and makes a separate list of the right sides of those for which f returned false.
The suffix rhr after the *| operator extracts the right side of the head of the right list from the result.
The operand to the *| operator, fleq@rlPlX is the less-or-equal predicate on floating point numbers, composed with the function ~&rlPlX which transforms a triple (u,(v,w)) to (v,u)

test program:

#cast %eL

test = price_fraction* <0.34,0.070145,0.06,0.05,0.50214,0.56,1.,0.99,0.>

Output:

<
   5.000000e-01,
   1.800000e-01,
   1.800000e-01,
   1.000000e-01,
   6.200000e-01,
   7.000000e-01,
   1.000000e+00,
   1.000000e+00,
   1.000000e-01>

VBScript

Function pf(p)
    If p < 0.06 Then 
        pf = 0.10
    ElseIf p < 0.11 Then 
    	pf = 0.18
    ElseIf p < 0.16 Then 
    	pf = 0.26
    ElseIf p < 0.21 Then 
    	pf = 0.32
    ElseIf p < 0.26 Then 
    	pf = 0.38
    ElseIf p < 0.31 Then 
    	pf = 0.44
    ElseIf p < 0.36 Then 
    	pf = 0.50
    ElseIf p < 0.41 Then 
    	pf = 0.54
    ElseIf p < 0.46 Then 
    	pf = 0.58
    ElseIf p < 0.51 Then 
    	pf = 0.62
    ElseIf p < 0.56 Then 
    	pf = 0.66
    ElseIf p < 0.61 Then 
    	pf = 0.70
    ElseIf p < 0.66 Then 
    	pf = 0.74
    ElseIf p < 0.71 Then 
    	pf = 0.78
    ElseIf p < 0.76 Then 
    	pf = 0.82
    ElseIf p < 0.81 Then 
    	pf = 0.86
    ElseIf p < 0.86 Then 
    	pf = 0.90
    ElseIf p < 0.91 Then 
    	pf = 0.94
    ElseIf p < 0.96 Then 
    	pf = 0.98
    Else 
    	pf = 1.00
    End If
End Function

WScript.Echo pf(0.7388727)
WScript.Echo pf(0.8593103)
WScript.Echo pf(0.826687)
WScript.Echo pf(0.3444635)

Output:

0.82
0.9
0.9
0.5

Wren

Library: Wren-fmt

import "./fmt" for Fmt

var rescale = Fn.new { |v|
    return (v < 0.06) ? 0.10 :
           (v < 0.11) ? 0.18 :
           (v < 0.16) ? 0.26 :
           (v < 0.21) ? 0.32 :
           (v < 0.26) ? 0.38 :
           (v < 0.31) ? 0.44 :
           (v < 0.36) ? 0.50 :
           (v < 0.41) ? 0.54 :
           (v < 0.46) ? 0.58 :
           (v < 0.51) ? 0.62 :
           (v < 0.56) ? 0.66 :
           (v < 0.61) ? 0.70 :
           (v < 0.66) ? 0.74 :
           (v < 0.71) ? 0.78 :
           (v < 0.76) ? 0.82 :
           (v < 0.81) ? 0.86 :
           (v < 0.86) ? 0.90 :
           (v < 0.91) ? 0.94 :
           (v < 0.96) ? 0.98 : 1.00
}

var tests = [0.49, 0.79, 1.00, 0.83, 0.99, 0.23, 0.12, 0.28, 0.72, 0.37, 0.95, 0.51, 0.43, 0.52, 0.84, 0.89, 0.48, 0.48, 0.30, 0.01]
for (test in tests) {
    Fmt.print("$4.2f -> $4.2f", test, rescale.call(test))
}

Output:

0.49 -> 0.62
0.79 -> 0.86
1.00 -> 1.00
0.83 -> 0.90
0.99 -> 1.00
0.23 -> 0.38
0.12 -> 0.26
0.28 -> 0.44
0.72 -> 0.82
0.37 -> 0.54
0.95 -> 0.98
0.51 -> 0.66
0.43 -> 0.58
0.52 -> 0.66
0.84 -> 0.90
0.89 -> 0.94
0.48 -> 0.62
0.48 -> 0.62
0.30 -> 0.44
0.01 -> 0.10

XPL0

include c:\cxpl\codes;  \intrinsic 'code' declarations

func real Price(V);     \Convert to standard value
real V;
[V:= V + 0.001;         \avoids possible rounding error i.e. 0.059999999
case of
  V < 0.06: ret 0.10;
  V < 0.11: ret 0.18;
  V < 0.16: ret 0.26;
  V < 0.21: ret 0.32;
  V < 0.26: ret 0.38;
  V < 0.31: ret 0.44;
  V < 0.36: ret 0.50;
  V < 0.41: ret 0.54;
  V < 0.46: ret 0.58;
  V < 0.51: ret 0.62;
  V < 0.56: ret 0.66;
  V < 0.61: ret 0.70;
  V < 0.66: ret 0.74;
  V < 0.71: ret 0.78;
  V < 0.76: ret 0.82;
  V < 0.81: ret 0.86;
  V < 0.86: ret 0.90;
  V < 0.91: ret 0.94;
  V < 0.96: ret 0.98
other       ret 1.00;
];

[Format(1,2);
RlOut(0, Price(0.0599));  CrLf(0);
RlOut(0, Price(0.10));  CrLf(0);
RlOut(0, Price(1.0));  CrLf(0);
]

Output:

0.18
0.18
1.00

zkl

fcn convert(price){ // float --> float
             //   <    -->, increments of 0.05 but tables are easier to update
   var vert=T( T(0.06, 0.10), T(0.11, 0.18), T(0.16, 0.26),
	       T(0.21, 0.32), T(0.26, 0.38), T(0.31, 0.44),
	       T(0.36, 0.50), T(0.41, 0.54), T(0.46, 0.58),
	       T(0.51, 0.62), T(0.56, 0.66), T(0.61, 0.70),
	       T(0.66, 0.74), T(0.71, 0.78), T(0.76, 0.82),
	       T(0.81, 0.86), T(0.86, 0.90), T(0.91, 0.94),
	       T(0.96, 0.98), T(1.01, 1.00), );
   vert.filter1('wrap([(a,_)]){ price<a })[1] 
}

fcn convert2(price){  // shifting the fractional part to the integer portion
   var vert=T(0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 
              0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00);
    vert[(price*100-1)/005];
}

T(0.7388727, 0.8593103, 0.826687, 0.3444635, 0.0491907).apply(convert) .println();
T(0.7388727, 0.8593103, 0.826687, 0.3444635, 0.0491907).apply(convert2).println();

Output:

L(0.82,0.9,0.9,0.5,0.1)
L(0.82,0.9,0.9,0.5,0.1)