public static complex operator *(complex a, complex b)
{
complex data = new complex((a.real * b.real) - (a.imag * b.imag),
(a.real * b.imag) + (a.imag * b.real));
return(data);
}
public static complex frompolar(double r, double theta)
{
complex data;
data = new complex(r * Math.Cos(theta), r * Math.Sin(theta));
return(data);
}
/// <summary>
/// calcul de DFT (discrete Fourier Transform)
/// version avec argument en entree de " type complex[] "
/// </summary>
/// <param name="x"> x[] : array of complex values </param>
/// <returns> DFT[] array of complex values </returns>
public static complex[] DFTv1(complex[] x)
{
int N = x.Length;
complex[] X = new complex[N];
for (int k = 0; k < N; k++)
{
X[k] = new complex(0, 0);
for (int n = 0; n < N; n++)
{
complex temp = complex.frompolar(1, -2 * Math.PI * n * k / N);
temp *= x[n];
X[k] += temp;
}
}
return(X);
}
public static complex operator -(complex a, complex b)
{
complex data = new complex(a.real - b.real, a.imag - b.imag);
return(data);
}