static void Example2D()
{
using (var input = new AlignedArrayComplex(16, 64, 16))
using (var output = new AlignedArrayComplex(16, input.GetSize()))
{
for (int row = 0; row < input.GetLength(0); row++)
{
for (int col = 0; col < input.GetLength(1); col++)
{
input[row, col] = (double)row * col / input.Length;
}
}
DFT.FFT(input, output);
DFT.IFFT(output, output);
for (int row = 0; row < input.GetLength(0); row++)
{
for (int col = 0; col < input.GetLength(1); col++)
{
Console.Write((output[row, col].Real / input[row, col].Real / input.Length).ToString("F2").PadLeft(6));
}
Console.WriteLine();
}
}
}
///<summary>
///This routine casts the output of FFTW engine to a Complex matrix, so the spectrum can be saved
///and manipulated
/// </summary>
/// <param name="FFTOutput">The FFT spectrum output in FFTW format</param>
/// <returns>Spectrum as matrix of double</returns>
private static Complex[,] CastFFTWToComplexSpectrum(AlignedArrayComplex FFTOutput)
{
int m = FFTOutput.GetLength(0);
int n = FFTOutput.GetLength(1);
double N_spe = (double)m * n;
Complex[,] spectrum = new Complex[m, n]; //Initialize spectrum
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
spectrum[i, j] = new Complex(FFTOutput[i, j].Real / N_spe, FFTOutput[i, j].Imaginary / N_spe);
}
}
return(spectrum);
}
public static cuDoubleComplex[] PerformFft(cuDoubleComplex[] data, int size, TransformDirection direction)
{
if (cudaAvailable)
{
return(cuHelper.PerformFFT(data, size, direction));
}
else
{
cuDoubleComplex[] result = new cuDoubleComplex[size * size];
using (var input = new AlignedArrayComplex(16, size, size))
using (var output = new AlignedArrayComplex(16, input.GetSize()))
{
for (int i = 0; i < input.GetLength(0); i++)
{
for (int j = 0; j < input.GetLength(1); j++)
{
input[i, j] = new Complex(data[i * size + j].real, data[i * size + j].imag);
}
}
if (direction == TransformDirection.Forward)
{
DFT.FFT(input, output);
}
else
{
DFT.IFFT(input, output);
}
for (int i = 0; i < input.GetLength(0); i++)
{
for (int j = 0; j < input.GetLength(1); j++)
{
result[i * size + j].real = output[i, j].Real;
result[i * size + j].imag = output[i, j].Imaginary;
}
}
}
return(result);
}
}
public static void Shift(AlignedArrayComplex grid)
{
var n2 = grid.GetLength(0) / 2;
for (int i = 0; i < n2; i++)
{
for (int j = 0; j < n2; j++)
{
var tmp13 = grid[i, j];
grid[i, j] = grid[i + n2, j + n2];
grid[i + n2, j + n2] = tmp13;
var tmp24 = grid[i + n2, j];
grid[i + n2, j] = grid[i, j + n2];
grid[i, j + n2] = tmp24;
}
}
}
