FFRACFT Approximate fast fractional Fourier transform
Usage: frf=ffracft(f,a)
frf=ffracft(f,a,dim)
FFRACFT(f,a) computes an approximation of the fractional Fourier
transform of the signal f to the power a. If f is
multi-dimensional, the transformation is applied along the first
non-singleton dimension.
FFRACFT(f,a,dim) does the same along dimension dim.
FFRACFT takes the following flags at the end of the line of input
arguments:
'origin' Rotate around the origin of the signal. This is the
same action as the DFT, but the signal will split in
the middle, which may not be the correct action for
data signals. This is the default.
'middle' Rotate around the middle of the signal. This will not
break the signal in the middle, but the DFT cannot be
obtained in this way.
Examples:
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The following example shows a rotation of the LTFATLOGO test
signal:
sgram(ffracft(ltfatlogo,.3,'middle'),'lin','nf');
References:
A. Bultheel and S. Martinez. Computation of the Fractional Fourier
Transform. Appl. Comput. Harmon. Anal., 16(3):182--202, 2004.
Url: http://ltfat.github.io/doc/fourier/ffracft.html
See also: dfracft, hermbasis, pherm.
Package: ltfat