/// <summary>
/// Returns the value of a derived function.
/// </summary>
/// <param name="y">Function vector</param>
/// <param name="index">Index of argument</param>
/// <param name="h">Step</param>
/// <param name="order">Order</param>
/// <returns>float precision floating point number</returns>
public float Compute(float[] y, int index, float h, int order)
{
// exception
if (order > this.points)
{
throw new Exception("The order of the derivative cannot be greater than the number of interpolation points");
}
if (order < 0)
{
throw new Exception("The derivative order cannot be less than 0");
}
// Create the interpolation points
int length = this.points + 1;
float[,] coefficients = Differentation.GetCoefficients(length);
float sum = 0.0f;
// do job
for (int i = 0, center = 0; i < length; i++)
{
sum += coefficients[order, i] * y[index + i];
center++;
}
// result
return(sum / (float)Math.Pow(h, order));
}
/// <summary>
/// Returns the value of a derived function.
/// </summary>
/// <param name="function">Continuous function delegate</param>
/// <param name="x">Argument value</param>
/// <param name="h">Step</param>
/// <param name="order">Order</param>
/// <returns>Complex number</returns>
public Complex32 Compute(IComplex function, Complex32 x, Complex32 h, int order)
{
// exception
if (order > this.points)
{
throw new Exception("The order of the derivative cannot be greater than the number of interpolation points");
}
if (order < 0)
{
throw new Exception("The derivative order cannot be less than 0");
}
// Create the interpolation points
int length = this.points + 1;
float[,] coefficients = Differentation.GetCoefficients(length);
Complex32 sum = 0.0;
// do job
for (int i = 0, center = 0; i < length; i++)
{
sum += coefficients[order, i] * function(x + center * h);
center++;
}
// result
return(sum / Maths.Pow(h, order));
}
