public Point Task2(Form form, Point location)
{
DkParameters parameters = new DkParameters()
{
Equations = new List <Func <double[], double> >()
{
Func2, Func3
},
Init = new double[] { 4, 6 },
Start = 0,
End = 2,
Delta = 0.05,
PassX = false
};
return(SolveInPointsRK(parameters).GetPlot().AddToForm(form, location));
}
public DkSolve SolveInPointsRK(DkParameters parameters)
{
double[] x = new double[(int)Math.Ceiling((parameters.End - parameters.Start) / parameters.Delta)];
for (int i = 0; i < x.Length; ++i)
{
x[i] = parameters.Delta * i + parameters.Start;
}
double[][] ys = new double[x.Length][];
ys[0] = parameters.Init;
for (int i = 0; i < x.Length - 1; ++i)
{
double[] prefix = parameters.PassX ? new double[] { x[i] } : new double[] { };
double[] prefixHalf = prefix.Add(0.5 * parameters.Delta);
double[] prefixFull = prefix.Add(parameters.Delta);
double[] k1 = parameters.Equations.Select(eq =>
eq(prefix.Concat(ys[i]).ToArray())
).ToArray();
double[] k2 = parameters.Equations.Select(
eq => eq(prefixHalf.Concat(k1.Multiply(0.5 * parameters.Delta).Add(ys[i])).ToArray())
).ToArray();
double[] k3 = parameters.Equations.Select(
eq => eq(prefixHalf.Concat(k2.Multiply(0.5 * parameters.Delta).Add(ys[i])).ToArray())
).ToArray();
double[] k4 = parameters.Equations.Select(
eq => eq(prefixFull.Concat(k3.Multiply(parameters.Delta).Add(ys[i])).ToArray())
).ToArray();
ys[i + 1] = ys[i].Add(k1.Add(k2.Multiply(2)).Add(k3.Multiply(2)).Add(k4).Multiply(parameters.Delta / 6));
}
return(new DkSolve()
{
X = x, Ys = ys
});
}
