Price fraction: Difference between revisions

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:

<lang Clipper>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</lang>

Sample output:

<pre> -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</pre>