[Numpy-discussion] Normalization of ifft

Pauli Virtanen pav@iki...
Fri Mar 27 05:53:16 CDT 2009


Thu, 26 Mar 2009 19:10:31 -0700, Lutz Maibaum wrote:
> On Thu, Mar 26, 2009 at 7:02 PM, Gideon Simpson
> <simpson@math.toronto.edu> wrote:
>> I thought it was the same as the MATLAB format:
>>
>> http://www.mathworks.com/access/helpdesk/help/techdoc/index.html?/
access/helpdesk/help/techdoc/ref/fft.html&http://www.google.com/search
>> ?client=safari&rls=en-us&q=MATLAB+fft&ie=UTF-8&oe=UTF-8
> 
> I believe this is true for the implementation, but I think the
> description of ifft in the NumPy User Guide might be incorrect.

Yes, the description of ifft in the "Guide to NumPy" book is probably 
incorrect:

>>> np.fft.ifft([1,0,0,0])
array([ 0.25+0.j,  0.25+0.j,  0.25+0.j,  0.25+0.j])

whereas that of the online reference guide is correct. (To avoid 
confusion between the different docs, it's probably best to use refer to 
the ebook by its name.)

-- 
Pauli Virtanen



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