I have a matrix from real space calculation from honeycomb lattice and I wish to Fourier transform the spatial part (of the data) to momentum space. However, FFT, FFT2 etc in matlab does not allow for variable (time or coordinate) inputs, one can only include the data, so there is no way to include the geometry of my system in the Fourier transform.
Is there a way I can use FFT with the coordinates of my system? If not is there another ''fast'' way to Fourier transform my data?
Thanks in advance.