/// <summary>
/// Plot solution
/// </summary>
/// <param name="sender">sender object</param>
/// <param name="e">Event arguments</param>
private void PlotButton_Click(object sender, EventArgs e)
{
pane.CurveList.Clear();
// Prey population equation
Func <double, double, double> preyPop = (x, y) =>
x * ((double)PreyBirthRate.Value - (double)PreyDeathRate.Value * y);
// Predator population equation
Func <double, double, double> predatorPop = (x, y) =>
y * ((double)PredatorBirthRate.Value * x - (double)PredatorDeathRate.Value);
// Solution for predator and prey
double[,] preyAndPredatorCurves;
try
{
// checking what algorith to use
if (RKF45.Checked)
{
preyAndPredatorCurves = RungeKutta.Rkf45(preyPop, predatorPop, (double)PreyPopulation.Value,
(double)PredatorPopulation.Value, (int)TimeSpan.Value, 0.01);
}
else
{
preyAndPredatorCurves = RungeKutta.Rk4(preyPop, predatorPop, (double)PreyPopulation.Value,
(double)PredatorPopulation.Value, (int)TimeSpan.Value, (double)StepSize.Value);
}
PointPairList preySolution = new PointPairList();
for (int i = 0; i <= preyAndPredatorCurves.GetUpperBound(1); i++)
{
preySolution.Add(preyAndPredatorCurves[2, i], preyAndPredatorCurves[0, i]);
}
PointPairList predatorSolution = new PointPairList();
for (int i = 0; i <= preyAndPredatorCurves.GetUpperBound(1); i++)
{
predatorSolution.Add(preyAndPredatorCurves[2, i], preyAndPredatorCurves[1, i]);
}
// Adding prey population curve
LineItem preyCurve = pane.AddCurve("Prey population",
preySolution, Color.Green, SymbolType.None);
preyCurve.Line.Width = 2;
preyCurve.Line.IsSmooth = true;
// Adding predator population curve
LineItem predatorCurve = pane.AddCurve("Predator population",
predatorSolution, Color.Red, SymbolType.None);
predatorCurve.Line.Width = 2;
predatorCurve.Line.IsSmooth = true;
}
catch (ArgumentException ex)
{
MessageBox.Show(ex.Message + "\nPlease enter smaller parameters", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
// Changing axis to fit the curves
GraphControl.AxisChange();
GraphControl.Invalidate();
}
