On 07/12/2010 11:43 AM, David Goldsmith wrote: > >From the docstring: > > "A[0] contains the zero-frequency term (the mean of the signal)" > > And yet, consistent w/ the definition given in the docstring (and > included w/ an earlier email), the code gives, e.g.: > > >>> import numpy as np > >>> x = np.ones((16,)); x > array([ 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., 1., > 1., 1., 1.]) > >>> y = np.fft.fft(x); y > array([ 16.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, > 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j, > 0.+0.j, 0.+0.j, 0.+0.j, 0.+0.j]) > > i.e., the zero-th term is the sum, not the mean (which, again, is > consistent w/ the stated defining formula). > > So, same ol', same ol': bug in the doc (presumably) or bug in the code?
Bug in the doc. Good catch. "mean" is correct for the ifft, not for the fft. Eric > > DG > > > > _______________________________________________ > NumPy-Discussion mailing list > [email protected] > http://mail.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
