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[bug-gsl] Error in documentation of real FFT (2008-05-12)

From: Cristian Toraci <cristian.toraci@.............>
Subject: Error in documentation of real FFT
Date: Mon, 12 May 2008 15:25:12 +0200
To: bug-gsl@gnu.org

Hi,

The documantation for gsl_fft_real_radix2_transform says that the output can be
sorted using gsl_fft_halfcomplex_unpack. The documantation of
gsl_fft_halfcomplex_unpack says it can also be used to sort the output of
gsl_fft_real_transform, but the output of gsl_fft_real_radix2_transform and
gsl_fft_real_transform don't have the same storage. Actually I verified than
gsl_fft_real_radix2_transform + gsl_fft_halfcomplex_unpack doesn't sort the
data in the right way: the result is different from what you get converting the
data to a complex array and transforming it with gsl_fft_complex_radix2_forward,
but the result is correct if the output of gsl_fft_real_radix2_transform is
sorted by hand.

Thank you.

--
Cristian Toraci
DIST - University of Genova
Viale Francesco Causa, 13
16145 Genova, Italy
tel. +39 010 3532789
fax. +39 010 3532948

cristian.toraci@.............
www.bio.dist.unige.it