Question

I’d like to use numpy to preform a double frequency transform. I have some data that is in the space-time domain and I would like to look at it in the frequency-wavenumber domain. I think numpy’s ft2 command can do this for me but I am a bit unsure how to implement it. My data is in a 2d array with shape (864000, 2) the first column is the spatial data and the second time. I tried the following,

ft2 = fft2(data)
plot(abs(ft2))

I get something that looks flat in the centre and blows up at the corners, which I dont think is right. Anyone know how to do this correctly???

Answer 1

ok I had misunderstood the usage, for fft2 the data needs to be an n by m matrix with each row should representing a different time increment, and each column should representing a different location.