Euler method: Difference between revisions

</pre>

=={{header|SequenceL}}==

<lang sequencel>import <Utilities/Conversion.sl>;

import <Utilities/Sequence.sl>;

T0 := 100.0;

TR := 20.0;

k := 0.07;

main(args(2)) :=

let

results[i] := euler(newtonCooling, T0, 100, stringToInt(args[i]), 0, "delta_t = " ++ args[i]);

in

delimit(results, '\n');

newtonCooling(t) := -k * (t - TR);

euler: (float -> float) * float * int * int * int * char(1) -> char(1);

euler(f, y, n, h, x, output(1)) :=

let

newOutput := output ++ "\n\t" ++ intToString(x) ++ "\t" ++ floatToString(y, 3);

newY := y + h * f(y);

newX := x + h;

in

output when x > n

else

euler(f, newY, n, h, newX, newOutput);</lang>

Based on C# version [http://rosettacode.org/wiki/Euler_method#C.23] but using tail recursion instead of looping.

{{out}}

For step size 10:

<pre>

main.exe 10

"delta_t = 10

0 100.000

10 44.000

20 27.200

30 22.160

40 20.648

50 20.194

60 20.058

70 20.017

80 20.005

90 20.002

100 20.000"