Temperature conversion
There are quite a number of temperature scales. For this task we will concentrate on 4 of the perhaps best-known ones: Kelvin, Celcius, Fahrenheit and Rankine.
The Celcius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celcius corresponds to 273.15 kelvin.
0 kelvin is absolute zero.
The Fahrenheit and Rankine scales also have the same magnitude, but different null points.
0 degrees Fahrenheit corresponds to 459.67 degrees Rankine.
0 degrees Rankine is absolute zero.
The Celcius/Kelvin and Fahrenheit/Rankine scales have a ratio of 5 : 9.
Write code that accepts a value of kelvin, converts it to values on the three other scales and prints the result. For instance:
K 21.00 C -252.15 F -421.87 R 37.80
D
<lang d>double kelvinToCelsius(in double k) pure nothrow @safe {
return k - 273.15;
}
double kelvinToFahrenheit(in double k) pure nothrow @safe {
return k * 1.8 - 459.67;
}
double kelvinToRankine(in double k) pure nothrow @safe {
return k * 1.8;
}
unittest {
import std.math: approxEqual; assert(approxEqual(kelvinToCelsius(21.0), -252.15)); assert(approxEqual(kelvinToFahrenheit(21.0), -421.87)); assert(approxEqual(kelvinToRankine(21.0), 37.8));
}
void main(string[] args) {
import std.stdio, std.conv, std.string;
if (args.length == 2 && isNumeric(args[1])) { immutable kelvin = to!double(args[1]); if (kelvin >= 0) { writefln("K %2.2f", kelvin); writefln("C %2.2f", kelvinToCelsius(kelvin)); writefln("F %2.2f", kelvinToFahrenheit(kelvin)); writefln("R %2.2f", kelvinToRankine(kelvin)); } else writefln("%2.2f K is below absolute zero", kelvin); }
}</lang>
- Output:
K 21.00 C -252.15 F -421.87 R 37.80
J
Solution:<lang j> NB. Temp conversions are all linear polynomials
K2K =: 0 1 NB. K = (1 *k) + 0 K2C =: _273 1 NB. C = (1 *k) - 273 K2F =: _459.67 1.8 NB. F = (1.8*k) - 459.67 K2R =: 0 1.8 NB. R = (1.8*k) + 0
NB. Do all conversions at once (eval NB. polynomials in parallel). This is the NB. numeric matrix J programs would manipulate NB. directly. k2KCFR =: (K2K , K2C , K2F ,: K2R) p./ ]</lang>
Example:<lang j> NB. Format matrix for printing
fmt =: '0.2' 8!:0 k2KCFR
NB. Tag each temp with scale, for human NB. legibility. kcfr =: 0 _1 |: 'KCFR' ,"0 1"_1 >@:fmt kcfr 21
K 21.00 C-252.00 F-421.87 R 37.80
kcfr 0 NB. Absolute zero
K 0.00 C-273.00 F-459.67 R 0.00
kcfr 21 100 300 NB. List of temps works fine
K 21.00 C-252.00 F-421.87 R 37.80
K 100.00 C-173.00 F-279.67 R 180.00
K 300.00 C 27.00 F 80.33 R 540.00
</lang>
Notes: The approach is founded on polynomials, one for each conversion (e.g. Fahrenheit = 1.8*x - 459.67 where x is measured in degrees Kelvin), and all polynomials are evaluated simultaneously using the built-in p.. Through some code decorations (specifically the / in p./ the "0 1"_1 and the 0 _1 |:), we permit our function to convert arrays of temperatures of arbitrarily high dimension (a single temp, lists of temps, tables of temps, cubes of temps, etc).
Java
<lang java>public class TemperatureConversion {
public static void main(String args[]) { if (args.length == 1) { try { double kelvin = Double.parseDouble(args[0]); if (kelvin >= 0) { System.out.printf("K %2.2f\n", kelvin); System.out.printf("C %2.2f\n", kelvinToCelcius(kelvin)); System.out.printf("F %2.2f\n", kelvinToFahrenheit(kelvin)); System.out.printf("R %2.2f\n", kelvinToRankine(kelvin)); } else { System.out.printf("%2.2f K is below absolute zero", kelvin); } } catch (NumberFormatException e) { System.out.println(e); } } }
public static double kelvinToCelcius(double k) { return k + 273.15; }
public static double kelvinToFahrenheit(double k) { return k * 1.8 - 459.67; }
public static double kelvinToRankine(double k) { return k * 1.8; }
}</lang>
K 21.00 C -252.15 F -421.87 R 37.80
МК-61/52
<lang>П7 0 , 8 * П8 ИП7 9 * 5 / 3 2 + П9 ИП7 2 7 3 , 1 5 + П4 С/П П8 1 , 8 / БП 00 П9 3 2 - 5 * 9 / БП 00 П4 2 7 3 , 1 5 - БП 00</lang>
Instruction:
tºC = РX В/О С/П;
tºRa = РX БП 25 С/П;
tºF = РX БП 32 С/П;
tK = РX БП 42 С/П;
Result:
РX = Р4 = tK;
Р7 = tºC;
Р8 = tºRa;
Р9 = tºF.
Perl 6
<lang perl6>while ne my $answer = prompt 'Temperature: ' {
my $k = do given $answer { when s/:i C $// { $_ + 273.15 } when s/:i F $// { ($_ + 459.67) / 1.8 } when s/:i R $// { $_ / 1.8 } when s/:i K $// { $_ } default { $_ } } say " { $k }K"; say " { $k - 273.15 }℃"; say " { $k * 1.8 - 459.67 }℉"; say " { $k * 1.8 }R";
}</lang>
- Output:
Temperature: 0 0K -273.15℃ -459.67℉ 0R Temperature: 0c 273.15K 0℃ 32℉ 491.67R Temperature: 212f 373.15K 100℃ 212℉ 671.67R Temperature: -40c 233.15K -40℃ -40℉ 419.67R
PHP
<lang php>error_reporting(E_ALL & ~ ( E_NOTICE | E_WARNING ));
while (true) {
echo "\nEnter a value in kelvin (q to quit): "; if (($kelvin = trim(fgets(STDIN))) !== false) { if ($kelvin == 'q') { echo 'quitting'; break; } if (is_numeric($kelvin)) { $kelvin = floatVal($kelvin); if ($kelvin >= 0) { printf(" K %2.2f\n", $kelvin); printf(" C %2.2f\n", $kelvin - 273.15); printf(" F %2.2f\n", $kelvin * 1.8 - 459.67); printf(" R %2.2f\n", $kelvin * 1.8); } else printf(" %2.2f K is below absolute zero\n", $kelvin); } }
}</lang>
Enter a value in kelvin (q to quit): 21 K 21.00 C -252.15 F -421.87 R 37.80 Enter a value in kelvin (q to quit): q quitting
Python
<lang python>>>> while True: k = float(input('K ? ')) print("%g Kelvin = %g Celsius = %g Fahrenheit = %g Rankine degrees." % (k, k - 273.15, k * 1.8 - 459.67, k * 1.8))
K ? 21.0
21 Kelvin = -252.15 Celsius = -421.87 Fahrenheit = 37.8 Rankine degrees.
K ? 222.2
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees.
K ? </lang>
Python: Universal conversion
This converts from any one of the units to all the others <lang python>>>> toK = {'C': (lambda c: c + 273.15),
'F': (lambda f: (f + 459.67) / 1.8), 'R': (lambda r: r / 1.8), 'K': (lambda k: k) }
>>> while True: magnitude, unit = input('<value> <K/R/F/C> ? ').split() k = toK[unit](float(magnitude)) print("%g Kelvin = %g Celsius = %g Fahrenheit = %g Rankine degrees." % (k, k - 273.15, k * 1.8 - 459.67, k * 1.8))
<value> <K/R/F/C> ? 222.2 K
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees.
<value> <K/R/F/C> ? -50.95 C
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees.
<value> <K/R/F/C> ? -59.71 F
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees.
<value> <K/R/F/C> ? 399.96 R
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit = 399.96 Rankine degrees.
<value> <K/R/F/C> ? </lang>
REXX
This REXX version supports:
- (alternate spellings with optional degrees):
- Centingrade, centesimal, Celsius, Celcius
- Delisle
- Fahrenheit
- Kelvin
- Newton
- Rankine
- Reaumur, Réaumur
- Romer (Rømer), Roemer
- multiple temperatures in a list
- comments within the list
- aligned output (whole numbers and decimal fractions)
<lang rexx>/*REXX program converts temperature for: C, D, F, N, Ra, Re, Ro, and K.*/ parse arg tList /*get specified temperature lists*/
do until tList= /*process a list of temperatures.*/ parse var tList x ',' tList /*temps are separated by commas. */ x=space(x); parse var x z '(' /*handle any comments (if any). */ if z== then call serr 'no arguments were specified.' _=verify(z, '+-.0123456789') /*a list of valid number thingys.*/ n=z if _\==0 then do if _==1 then call serr 'illegal temperature:' z n=left(z, _-1) /*pick off the number (hopefully)*/ u=strip(substr(z, _)) /*pick off the temperature unit. */ end else u='k' /*assume Kelvin as per task req.*/
uU=translate(u,'EE',"éÉ"); upper uU /*uppercase version of temp unit.*/ if left(uU,7)=='DEGREES' then uU=substr(uU,8) /*redundant "degrees"? */ if left(uU,5)=='DEGREE' then uU=substr(uU,7) /* " "degree" ? */ uU=strip(uU) if \datatype(n,'N') then call serr 'illegal number:' n /*accept alternate spellings. */ select /*convert ──► ºF temperatures. */ when abbrev('CENTIGRADE', uU) |, abbrev('CENTESIMAL', uU) |, abbrev('CELSIUS' , uU) |, abbrev('CELCIUS' , uU) then F=n * 9/5 + 32 when abbrev('DELISLE' , uU) then F=212 -(n * 6/5) when abbrev('FAHRENHEIT', uU) then F=n when abbrev('KELVIN' , uU) then F=n * 9/5 - 459.67 when abbrev('NEWTON' , uU) then F=n * 60/11 + 32 when abbrev('RANKINE' , uU) then F=n - 459.67 when abbrev('REAUMUR' , uU, 2) then F=n * 9/4 + 32 when abbrev('ROEMER' , uU, 2) |, abbrev('ROMER' , uU, 2) then F=(n-7.5) * 27/4 + 32 otherwise call serr 'illegal temperature scale:' u end /*select*/ say right(' ' x,55,"─") say Tform( ( F - 32 ) * 5/9 ) 'Celcius' say Tform( ( 212 - F ) * 5/6 ) 'Delisle' say Tform( F ) 'Fahrenheit' say Tform( ( F + 459.67 ) * 5/9 ) 'Kelvin' say Tform( ( F - 32 ) * 11/60 ) 'Newton' say Tform( F + 459.67 ) 'Rankine' say Tform( ( F - 32 ) * 4/9 ) 'Reaumur' say Tform( ( F - 32 ) * 7/24 + 7.5 ) 'Romer' end /*until tlist=*/
exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────TFORM subroutine────────────────────*/ Tform: procedure; showDig=8; _=format(arg(1),,showDig)/1; p=pos('.',_) if p==0 then _=_ || left(,showDig+1)
else _=_ || left(,showDig-length(_)+p); return right(_,20)
/*──────────────────────────────────SERR subroutine─────────────────────*/ serr: say; say '***error!***'; say; say arg(1); say; exit 13</lang> output when using the input of: -40C, 0 c (water freezes), 37C (body temp), 100 C (water boils), 21 degrees Kelvin, 0K (outer space?)
───────────────────────────────────────────────── -40c -40 Celcius 210 Delisle -40 Fahrenheit 233.15 Kelvin -13.2 Newton 419.67 Rankine -32 Reaumur -13.5 Romer ─────────────────────────────────────────────────── 0c 0 Celcius 150 Delisle 32 Fahrenheit 273.15 Kelvin 0 Newton 491.67 Rankine 0 Reaumur 7.5 Romer ────────────────────────────────────────────────── 37c 37 Celcius 94.5 Delisle 98.6 Fahrenheit 310.15 Kelvin 12.21 Newton 558.27 Rankine 29.6 Reaumur 26.925 Romer ───────────────────────────────────────────────── 100c 100 Celcius 0 Delisle 212 Fahrenheit 373.15 Kelvin 33 Newton 671.67 Rankine 80 Reaumur 60 Romer ────────────────────────────────────────────────── 21k -252.15 Celcius 528.225 Delisle -421.87 Fahrenheit 21 Kelvin -83.2095 Newton 37.8 Rankine -201.72 Reaumur -124.87875 Romer ─────────────────────────────────────────────────── 0k -273.15 Celcius 559.725 Delisle -459.67 Fahrenheit 0 Kelvin -90.1395 Newton 0 Rankine -218.52 Reaumur -135.90375 Romer
[Actually, water freezes at 0.000089º C, and boils at 99.974º C.]