private void button1_Click(object sender, EventArgs e)
{
double t0, tmax, tau;
t0 = Convert.ToDouble(tbT0.Text);
tmax = Convert.ToDouble(tbTmax.Text);
tau = Convert.ToDouble(tbTau.Text);
double[] mass = {};
double t = t0;
int n = 3;
double[] ynach = new double[n];
ynach[0] = 1.0;
ynach[1] = 1.0;
ynach[2] = 0.0;
MathFuncsDiffEquations myfunc = new MathFuncsDiffEquations();
if (rbEiler.Checked)
{
richTextBox1.Clear();
mass = myfunc.Eiler(t0, tmax, tau, n, ynach, diffEqu);
for (int i = 1; i < (int)((tmax - t0) / tau); i++)
{
t += tau;
richTextBox1.Text += String.Format("time={0} y1={1:f6} y2={2:f6} y3={3:f6}", t, mass[i * 3],
mass[1 + i * 3],
mass[2 + i * 3]) + Environment.NewLine;
}
}
if (rbRK2.Checked)
{
richTextBox1.Clear();
mass = myfunc.RK2(t0, tmax, tau, n, ynach, diffEqu);
for (int i = 1; i < (int)((tmax - t0) / tau); i++)
{
t += tau;
richTextBox1.Text += String.Format("time={0} y1={1:f6} y2={2:f6} y3={3:f6}", t, mass[i * 3],
mass[1 + i * 3],
mass[2 + i * 3]) + Environment.NewLine;
}
}
if (rbRK4.Checked)
{
richTextBox1.Clear();
mass = myfunc.RK4(t0, tmax, tau, n, ynach, diffEqu);
for (int i = 1; i < (int)((tmax - t0) / tau); i++)
{
t += tau;
richTextBox1.Text += String.Format("time={0} y1={1:f6} y2={2:f6} y3={3:f6}", t, mass[i * 3],
mass[1 + i * 3],
mass[2 + i * 3]) + Environment.NewLine;
}
}
}
public void DiffEiler()
{
double[] mass = { };
double t0 = 0.0, tmax = 0.1, tau = 0.01;
int n = 3;
double[] ynach = new double[n];
ynach[0] = 1.0;
ynach[1] = 1.0;
ynach[2] = 0.0;
mass = mydiff.Eiler(t0, tmax, tau, n, ynach, diffEqu);
int nn = (int)((tmax - t0) / tau) - 1;
Assert.AreEqual(Math.Round(mass[nn * n], 6), 1.182412);
Assert.AreEqual(Math.Round(mass[nn * n + 1], 6), 1.001024);
Assert.AreEqual(Math.Round(mass[nn * n + 2], 6), 0.010308);
}