private void DrawWithEulerMethod(BaseChart chart, Series series, double x, double y, double[] parameters)
{
for (int i = 0; i < _iterations; i += IterationsStep)
{
series.Points.AddXY(x, y);
/*Если попытаться написать x += _stepValue * chart.f(x, y); y += _stepValue * chart.g(x, y);
* То теряются какие то знаки после запятой, почему?
* */
double nextX = x + _stepValue * chart.f(x, y);
double nextY = y + _stepValue * chart.g(x, y);
x = nextX;
y = nextY;
}
}
private void Draw_Button_Click(object sender, EventArgs e)
{
if (AreFieldsEmpty())
{
return;
}
string choosedChart = ChooseChart_ComboBox.SelectedItem.ToString();
string choosedMethod = ChooseMethod_ComboBox.SelectedItem.ToString();
var startX = 1.0;
var startY = 0.0;
var stepValue = 0.0;
var iterations = 0;
if (StartX_TextBox.Text.Length != 0 && StartY_TextBox.Text.Length != 0)
{
if (!double.TryParse(StartX_TextBox.Text, out startX) || !double.TryParse(StartY_TextBox.Text, out startY))
{
MessageBox.Show("Недопустимые координаты.");
return;
}
}
if (StepValue_TextBox.Text.Length != 0 && !double.TryParse(StepValue_TextBox.Text, out stepValue))
{
MessageBox.Show("Недопустимое значение шага.");
return;
}
if (Iterations_TextBox.Text.Length != 0 && !int.TryParse(Iterations_TextBox.Text, out iterations) ||
iterations < 0)
{
MessageBox.Show("Недопустимое количество итераций.");
return;
}
BaseChart chartType = GetChartType();
double[] parameters = GetParameters();
string methodName = ChooseMethod_ComboBox.SelectedItem.ToString();
_manager.Draw(chartType, methodName, startX, startY, stepValue, iterations, parameters);
}
public void Draw(BaseChart chart, string method, double startX, double startY,
double stepValue, int iterations, double[] parameters)
{
_stepValue = stepValue == 0 ? Default_stepValue : stepValue;
_iterations = iterations == 0 ? DefaultIterations : iterations;
string fullName = GetFullName(chart.BaseName, startX, startY, parameters);
if (_chart.Series.FindByName(fullName) == null)
{
SetupSeries(fullName);
}
if (method.Equals("Метод Эйлера"))
{
DrawWithEulerMethod(chart, _chart.Series[fullName], startX, startY, parameters);
}
else if (method.Equals("Метод Рунге-Кутта"))
{
DrawWithRungeKutt(chart, _chart.Series[fullName], startX, startY, parameters);
}
}
private void DrawWithRungeKutt(BaseChart chart, Series series, double x, double y, double[] parameters)
{
for (int i = 0; i < _iterations; i += IterationsStep)
{
double k1 = _stepValue * chart.f(x, y, parameters);
double l1 = _stepValue * chart.g(x, y, parameters);
double k2 = _stepValue * chart.f(x + k1 / 2, y + l1 / 2, parameters);
double l2 = _stepValue * chart.g(x + k1 / 2, y + l1 / 2, parameters);
double k3 = _stepValue * chart.f(x + k2 / 2, y + l2 / 2, parameters);
double l3 = _stepValue * chart.g(x + k2 / 2, y + l2 / 2, parameters);
double k4 = _stepValue * chart.f(x + k3, y + l3, parameters);
double l4 = _stepValue * chart.g(x + k3, y + l3, parameters);
series.Points.AddXY(x, y);
x += RungeKuttConst * Math.Round(k1 + 2 * k2 + 2 * k3 + k4, 5);
y += RungeKuttConst * Math.Round(l1 + 2 * l2 + 2 * l3 + l4, 5);
}
}