public static extern IntPtr dft_2d(int nx, int ny, IntPtr input, IntPtr output, InteropFFTWDirection direction, InteropFFTWFlags flags);
public static extern IntPtr dft_3d(int nx, int ny, int nz, IntPtr input, IntPtr output, InteropFFTWDirection direction, InteropFFTWFlags flags);
public static extern IntPtr dft(int rank, int[] n, IntPtr input, IntPtr output, InteropFFTWDirection direction, InteropFFTWFlags flags);