# [SciPy-user] Fourier-sine transform with SciPy

Lubos Vrbka lists@vrbka....
Fri Jun 6 02:10:54 CDT 2008

hi guys,

i'm a new (and so far very happy) user of the scipy bundle. however, i
have a problem at the moment, and i don't know how to solve it (apart
from somehow writing slow and unoptimized transform routine myself).

i need to perform a discrete fourier transform of a radially symmetric
function, dependent only on the |r| and |k| in real and fourier space,
respectively. after some straightforward math, i arrived at the
expression for the sine transform (continuous transform), namely
F(k) = A \int_0^\infty f(r) sin(kr) dr (FT)
f(r) = B \int_0^\infty f(k) sin(kr) dk (iFT)
with A and B being constant coefficients. naturally this has got the
advantage of just one function being needed to perform the transform
(just with different coefficient every time).

the problem is, that i don't know how (and whether it actually is
posible) to perform this task (discrete sine transform) with scipy.
searching the google and lists wasn't of much help, either.

i know that for example fftw includes the function for sine and cosine
transforms, but i didn't find any connection between the fftw functions
and scipy.fft, that would be younger than several years.

i would be grateful for any help or hint.

with best regards,

--
Lubos _@_"
http://www.lubos.vrbka.net