Temperature conversion

Temperature conversion
You are encouraged to solve this task according to the task description, using any language you may know.

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

Ada

<lang Ada>with Ada.Float_Text_IO, Ada.Text_IO; use Ada.Float_Text_IO, Ada.Text_IO;

procedure Temperatur_Conversion is

  K: Float;
  function C return Float is (K - 273.15);
  function F return Float is (K * 1.8 - 459.67);
  function R return Float is (K * 1.8);

begin

  Get(K); New_Line;                                           -- Format 
  Put("K: "); Put(K, Fore => 4, Aft => 2, Exp => 0); New_Line;-- K: dddd.dd
  Put("C: "); Put(C, Fore => 4, Aft => 2, Exp => 0); New_Line;-- C: dddd.dd
  Put("F: "); Put(F, Fore => 4, Aft => 2, Exp => 0); New_Line;-- F: dddd.dd
  Put("R: "); Put(R, Fore => 4, Aft => 2, Exp => 0); New_Line;-- R: dddd.dd

end;</lang>

Output:

21.0

K:   21.00
C: -252.15
F: -421.87
R:   37.80

AWK

<lang AWK># syntax: AWK -f TEMPERATURE_CONVERSION.AWK BEGIN {

   while (1) {
     printf("\nKelvin degrees? ")
     getline K
     if (K ~ /^$/) {
       break
     }
     if (K < 0) {
       print("K must be > 0")
       continue
     }
     printf("K = %.2f\n",K)
     printf("C = %.2f\n",K - 273.15)
     printf("F = %.2f\n",K * 1.8 - 459.67)
     printf("R = %.2f\n",K * 1.8)
   }
   exit(0)

}</lang>

BASIC

<lang basic>10 REM TRANSLATION OF AWK VERSION 20 INPUT "KELVIN DEGREES",K 30 IF K <= 0 THEN END: REM A VALUE OF ZERO OR LESS WILL END PROGRAM 40 LET C = K - 273.15 50 LET F = K * 1.8 - 459.67 60 LET R = K * 1.8 70 PRINT K; " KELVIN IS EQUIVALENT TO" 80 PRINT C; " DEGREES CELCIUS" 90 PRINT F; " DEGREES FAHRENHEIT" 100 PRINT R; " DEGREES RANKINE" 110 GOTO 20</lang>

BBC BASIC

<lang bbcbasic> REPEAT

 INPUT "Kelvin degrees (>=0): " K

UNTIL K>=0 @%=&20208 PRINT '"K = " K PRINT "C = " K - 273.15 PRINT "F = " K * 1.8 - 459.67 PRINT "R = " K * 1.8 END </lang> Output:

Kelvin degrees (>=0): 21

K =    21.00
C =  -252.15
F =  -421.87
R =    37.80

C

<lang c>#include <stdio.h>

1. include <stdlib.h>

double kelvinToCelsius(double k){

   return k - 273.15;

}

double kelvinToFahrenheit(double k){

   return k * 1.8 - 459.67;

}

double kelvinToRankine(double k){

   return k * 1.8;

} void convertKelvin(double kelvin) {

   printf("K %.2f\n", kelvin);
   printf("C %.2f\n", kelvinToCelsius(kelvin));
   printf("F %.2f\n", kelvinToFahrenheit(kelvin));
   printf("R %.2f", kelvinToRankine(kelvin));

}

int main(int argc, const char * argv[]) {

   if (argc > 1) {
       double kelvin = atof(argv[1]);
       convertKelvin(kelvin);
   }
   return 0;

}</lang>

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

Erlang

<lang erlang>% Implemented by Arjun Sunel -module(temp_conv). -export([main/0]).

main() -> conversion(21).

conversion(T) -> io:format("\nK : ~p\n\n",[f(T)]), io:format("C : ~p \n\n",[f(T - 273.15)]), io:format("F : ~p\n\n",[f(T * 1.8 - 459.67)]), io:format("R : ~p\n\n",[f(T * 1.8)]).

f(A) -> (round(A*100))/100 . </lang>

Output:

K : 21.0

C : -252.15 

F : -421.87

R : 37.8

ok

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>

Output:

K  21.00

C  -252.15

F  -421.87

R  37.80

Julia

<lang julia>cfr(k) = print("Kelvin: $k, Celsius: $(round(k-273.15,2)), Fahrenheit: $(round(k*1.8-459.67,2)), Rankine: $(round(k*1.8,2))")</lang>

julia> cfr(21)
Kelvin: 21, Celsius: -252.15, Fahrenheit: -421.87, Rankine: 37.8

Mathematica

<lang Mathematica>tempConvert[t_] := Grid[Transpose@{{"K", "C", "F", "R"}, Round[{t, t - 273.15, 9 t/5 - 459.67, 9 t/5}, .01]}]

tempConvert[21]</lang>

Output:

K	21.
C	-252.15
F	-421.87
R	37.8

МК-61/52

<lang mk61>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.

Objeck

<lang objeck> class Temperature {

 function : Main(args : String[]) ~ Nil {
   k := System.IO.Console->ReadString()->ToFloat();
   c := KelvinToCelcius(k);
   f := KelvinToFahrenheit(k);
   r := KelvinToRankine(k);

   "K: {$k}"->PrintLine();
   "C: {$c}"->PrintLine();
   "F: {$f}"->PrintLine();
   "R: {$r}"->PrintLine();
 }

 function : KelvinToCelcius(k : Float) ~ Float {
   return k - 273.15;
 }

 function : KelvinToFahrenheit(k : Float) ~ Float {
   return k * 1.8 - 459.67;
 }

 function : KelvinToRankine(k : Float) ~ Float {
   return k * 1.8;
 }

} </lang>

K: 21.0
C: -252.150
F: -421.870
R: 37.800

Objective-C

<lang objc>#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {

   @autoreleasepool {
       if(argc > 1)
       {
           NSString *arg1 = [NSString stringWithCString:argv[1] encoding:NSUTF8StringEncoding]; 
           // encoding shouldn't matter in this case
           double kelvin = [arg1 doubleValue];
           
           NSLog(@"K %.2f",kelvin);
           NSLog(@"C %.2f\n", kelvin - 273.15);
           NSLog(@"F %.2f\n", (kelvin * 1.8) - 459.67);
           NSLog(@"R %.2f", kelvin * 1.8);
       }
   }
   return 0;

}</lang>

PARI/GP

<lang parigp>f(x)=[x,x-273.15,1.8*x-459.67,1.8*x]</lang>

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>

Output:

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>

Racket

Althoguh not exactly the shortest code, the converter function can turn any temperature into any other <lang Racket>#lang racket (define (converter temp init final)

 (define to-k
   (case init
     ('k temp)
     ('c (+ 273.15 temp))
     ('f (* (+ temp 459.67) 5/9))
     ('r (* temp 5/9))))
 (case final
   ('k to-k)
   ('c (- to-k 273.15))
   ('f (- (* to-k 9/5) 459.67))
   ('r (* to-k 1.8))))

(define (kelvin-to-all temp)

 (display (format "Kelvin: ~a \nCelsius: ~a \nFahrenheit: ~a \nRankine: ~a \n"
                  temp
                  (converter temp 'k 'c)
                  (converter temp 'k 'f)
                  (converter temp 'k 'r))))

(kelvin-to-all 21)

Kelvin

21

Celsius

-252.14999999999998

Fahrenheit

-421.87

Rankine

37.800000000000004

</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.]

Run BASIC

<lang runbasic>[loop] input "Lelvin Degrees";kelvin if kelvin <= 0 then end ' zero or less ends the program celcius = kelvin - 273.15 fahrenheit = kelvin * 1.8 - 459.67 rankine = kelvin * 1.8 print kelvin;" kelvin is equal to ";celcius; " degrees celcius and ";fahrenheit;" degrees fahrenheit and ";rankine; " degrees rankine" goto [loop]</lang>

Tcl

<lang tcl>proc temps {k} {

   set c [expr {$k - 273.15}]
   set r [expr {$k / 5.0 * 9.0}]
   set f [expr {$r - 459.67}]
   list $k $c $f $r

}</lang> Demonstrating: <lang tcl>puts -nonewline "Enter a temperature in K: " flush stdout lassign [temps [gets stdin]] k c f r puts [format "K: %.2f" $k] puts [format "C: %.2f" $c] puts [format "F: %.2f" $f] puts [format "R: %.2f" $r]</lang>

Output:

Enter a temperature in K: 21
K: 21.00
C: -252.15
F: -421.87
R: 37.80

XPL0

<lang XPL0>include c:\cxpl\codes; real K, C, F, R; [ChOut(0, ^K); K:= RlIn(0); C:= K - 273.15; ChOut(0, ^C); RlOut(0, C); CrLf(0); F:= 1.8*C + 32.0; ChOut(0, ^F); RlOut(0, F); CrLf(0); R:= F + 459.67; ChOut(0, ^R); RlOut(0, R); CrLf(0); ]</lang>

Output:

K 21
C -252.15000
F -421.87000
R   37.80000

ZX Spectrum Basic

<lang zxbasic>10 REM Translation of traditional basic version 20 INPUT "Kelvin Degrees? ";k 30 IF k <= 0 THEN STOP: REM A value of zero or less will end program 40 LET c = k - 273.15 50 LET f = k * 1.8 - 459.67 60 LET r = k * 1.8 70 PRINT k; " Kelvin is equivalent to" 80 PRINT c; " Degrees Celcius" 90 PRINT f; " Degrees Fahrenheit" 100 PRINT r; " Degrees Rankine" 110 GO TO 20</lang>