Euler method: Difference between revisions
Add Dart implementation
(Add MATLAB implementation) |
(Add Dart implementation) |
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Line 968:
90.000 20.002
done</pre>
=={{header|Dart}}==
{{trans|Swift}}
<syntaxhighlight lang="Dart">
import 'dart:math';
import "dart:io";
const double k = 0.07;
const double initialTemp = 100.0;
const double finalTemp = 20.0;
const int startTime = 0;
const int endTime = 100;
void ivpEuler(double Function(double, double) function, double initialValue, int step) {
stdout.write(' Step ${step.toString().padLeft(2)}: ');
var y = initialValue;
for (int t = startTime; t <= endTime; t += step) {
if (t % 10 == 0) {
stdout.write(y.toStringAsFixed(3).padLeft(7));
}
y += step * function(t.toDouble(), y);
}
print('');
}
void analytic() {
stdout.write(' Time: ');
for (int t = startTime; t <= endTime; t += 10) {
stdout.write(t.toString().padLeft(7));
}
stdout.write('\nAnalytic: ');
for (int t = startTime; t <= endTime; t += 10) {
var temp = finalTemp + (initialTemp - finalTemp) * exp(-k * t);
stdout.write(temp.toStringAsFixed(3).padLeft(7));
}
print('');
}
double cooling(double t, double temp) {
return -k * (temp - finalTemp);
}
void main() {
analytic();
ivpEuler(cooling, initialTemp, 2);
ivpEuler(cooling, initialTemp, 5);
ivpEuler(cooling, initialTemp, 10);
}
</syntaxhighlight>
{{out}}
<pre>
Time: 0 10 20 30 40 50 60 70 80 90 100
Analytic: 100.000 59.727 39.728 29.797 24.865 22.416 21.200 20.596 20.296 20.147 20.073
Step 2: 100.000 57.634 37.704 28.328 23.918 21.843 20.867 20.408 20.192 20.090 20.042
Step 5: 100.000 53.800 34.280 26.034 22.549 21.077 20.455 20.192 20.081 20.034 20.014
Step 10: 100.000 44.000 27.200 22.160 20.648 20.194 20.058 20.017 20.005 20.002 20.000
</pre>
=={{header|Delphi}}==
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