public static List <double> RungeKut(Math.Interval interval, FuncDiff func, double y0)
{
if (!interval.isValid)
{
return(null);
}
double deltaY, yNext, yPrev;
List <double> result = new List <double>();
yPrev = y0;
double k1, k2, k3, k4;
foreach (double x in interval.Points)
{
k1 = interval.Step * func(x, y0);
k2 = interval.Step * func(x + (interval.Step / 2), y0 + (k1 / 2));
k3 = interval.Step * func(x + (interval.Step / 2), y0 + (k2 / 2));
k4 = interval.Step * func(x + interval.Step, y0 + k3);
deltaY = (k1 + 2 * k2 + 2 * k3 + k4);
deltaY /= 6;
yNext = y0 + deltaY;
result.Add(y0);
y0 = yNext;
}
return(result);
}
public static List <double> EilerPlus(ref Math.Interval interval, FuncDiff func, double y0)
{
if (!interval.isValid)
{
return(null);
}
double deltaY, yNext, yPrev;
List <double> result = new List <double>();
yPrev = y0;
bool parity = true;
interval.PointsCount = interval.PointsCount * 2 - 1;
foreach (double x in interval.Points)
{
if (parity)
{
deltaY = interval.Step * func(x, y0);
yNext = y0 + deltaY;
}
else
{
deltaY = 2 * interval.Step * func(x, y0);
yNext = yPrev + deltaY;
}
result.Add(y0);
yPrev = y0;
y0 = yNext;
parity = !parity;
}
return(result);
}
public static List <double> Eiler(Math.Interval interval, FuncDiff func, double y0)
{
if (!interval.isValid)
{
return(null);
}
double deltaY, yNext;
List <double> result = new List <double>();
foreach (double x in interval.Points)
{
deltaY = interval.Step * func(x, y0);
yNext = y0 + deltaY;
result.Add(y0);
y0 = yNext;
}
return(result);
}