//Model
private void plot_Computation()
{
try
{
exact = new Exact(N, x_0, y_0, x_max);
eu = new Euler(N, x_0, y_0, x_max);
ie = new Euler_Impr(N, x_0, y_0, x_max);
rk = new Runge_Kutta(N, x_0, y_0, x_max);
eu.LTE(exact);
ie.LTE(exact);
rk.LTE(exact);
plot_Draw(null, null);
}
catch (DiscontinuityException ex)
{
MessageBox.Show("There is a point of discontinuity in the x interval (x = " + ex.Message + ")",
"Discontinuity", MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
catch (Exception exp)
{
MessageBox.Show("Something does wrong...\n" + exp.Message, "Error",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
internal void LTE(Exact e)
{
er = new double[y.Length];
for (int i = 0; i < y.Length; i++)
{
er[i] = Math.Abs(e.y[i] - y[i]);
}
}
private void change_err_Click(object sender, EventArgs e)
{
if (N_mode == false)
{
try
{
int N_start = Int32.Parse(enter_N_start.Text);
int N_end = Int32.Parse(enter_N_end.Text);
if (N_start <= 0) throw new WrongDataException("Start N must be greater than 0");
if (N_end <= N_start) throw new WrongDataException("Upper bound N have to be greater than start N");
double[] max_er_eu = new double[N_end - N_start + 1];
double[] max_er_ie = new double[N_end - N_start + 1];
double[] max_er_rk = new double[N_end - N_start + 1];
double[] N_ = new double[N_end - N_start + 1];
int index = 0;
for (int i = N_start; i <= N_end; i++)
{
Exact exact_N = new Exact(i, x_0, y_0, x_max);
Euler eu_N = new Euler(i, x_0, y_0, x_max);
eu_N.LTE(exact_N);
max_er_eu[index] = eu_N.max_LTE();
Euler_Impr ie_N = new Euler_Impr(i, x_0, y_0, x_max);
ie_N.LTE(exact_N);
max_er_ie[index] = ie_N.max_LTE();
Runge_Kutta rk_N = new Runge_Kutta(i, x_0, y_0, x_max);
rk_N.LTE(exact_N);
max_er_rk[index] = rk_N.max_LTE();
N_[index] = i;
index++;
}
Errors.ChartAreas[0].AxisX.Minimum = N_start;
Errors.ChartAreas[0].AxisX.Maximum = N_end;
Errors.Series[0].Points.DataBindXY(N_, max_er_eu);
Errors.Series[1].Points.DataBindXY(N_, max_er_ie);
Errors.Series[2].Points.DataBindXY(N_, max_er_rk);
N_mode = true;
change_err.Text = "Back to LTE to x dependence";
}
catch (DiscontinuityException ex)
{
MessageBox.Show("There is a point of discontinuity in the x interval (x = " + ex.Message + ")",
"Discontinuity", MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
catch (WrongDataException exp)
{
MessageBox.Show(exp.Message, "Wrong data",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
catch(FormatException)
{
MessageBox.Show("Only integer numbers are allowed to enter", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
catch (Exception exp)
{
MessageBox.Show("Something does wrong...\n" + exp.Message, "Error",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
else
{
Errors.ChartAreas[0].AxisX.Minimum = x_0;
Errors.ChartAreas[0].AxisX.Maximum = x_max;
Errors.Series[0].Points.DataBindXY(eu.x, eu.er);
Errors.Series[1].Points.DataBindXY(ie.x, ie.er);
Errors.Series[2].Points.DataBindXY(rk.x, rk.er);
change_err.Text = "Explore max_LTE to N dependence";
N_mode = false;
}
}
