Re: [Numpy-discussion] fft help

2011-12-29 Thread Burlen Loring
hmmph, I used both fftn and fft2, they both produce the same result. Is there a restriction on the dimension of the input? power of 2 or some such? On 12/29/2011 07:21 AM, Torgil Svensson wrote: This is because fft computes one-dimensional transforms (on each row). Try fft2 instead. //Torgil

Re: [Numpy-discussion] fft help

2011-12-29 Thread Torgil Svensson
Sorry, i should have looked at your image. A few test you can do is 1) does ifft2 give you back the original image? (allclose returned True for a little test I did here) 2) does scipy.fftpack.fft2 yield the same result? //Torgil On Thu, Dec 29, 2011 at 6:32 PM, Burlen Loring

Re: [Numpy-discussion] fft help

2011-12-29 Thread Torgil Svensson
This is because fft computes one-dimensional transforms (on each row). Try fft2 instead. //Torgil fft(a, n=None, axis=-1) Compute the one-dimensional discrete Fourier Transform. fft2(a, s=None, axes=(-2, -1)) Compute the 2-dimensional discrete Fourier Transform fftn(a, s=None,

Re: [Numpy-discussion] fft help

2011-12-29 Thread Burlen Loring
there seems to be some undocumented restriction on dimensions as when I work with 512x512 data things work as expected. On 12/29/2011 09:43 AM, Torgil Svensson wrote: Sorry, i should have looked at your image. A few test you can do is 1) does ifft2 give you back the original image? (allclose

[Numpy-discussion] fft help

2011-12-28 Thread Burlen Loring
Hi I have an image I need to do an fft on, I tried numpy.fft but results are not what I expected, and differ from matlab. My input image is a weird size, 5118x1279, I think numpy fft is not liking it. In numpy the fft appears to be computed multiple times and tiled across the output image. In