[SciPy-dev] DCT naming conventions ?

David Cournapeau david@ar.media.kyoto-u.ac...
Sun Jan 18 05:18:30 CST 2009


Hi,

    I needed DCT transforms, so I finished implementing them in scipy
(both single and double prec):

http://projects.scipy.org/scipy/scipy/browser/trunk/scipy/fftpack/realtransforms.py

I followed the definitions of wikipedia/fftw, using the fftpack
implementations. I am not sure about naming conventions:
    - dct2 is the type II DCT, not the 2dimension DCT (multidimensional
dcts are not implemented - I don't need them myself)
    - dct3 and dct2 are inverse from each other (compared to dct/idct
notation of matlab; dct2(x, norm=ortho) is the same as matlab dct(x),
and dct3(x, norm='ortho') is the same as matlab idct.

Unless someone has a better idea/suggestion, I will put those
definitions in scipy.fftpack namespace in a couple of days,

cheers,

David


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