The gslfft
may be used to compute N dimensional fast fourier
transforms (FFT). The module itself currently provides a single function
called _gsl_fft_complex
that performs a forward or backward
n-dimensional FFT. The underlying GSL routines used by this
function are the Swarztrauber mixed-radix routines from FFTPACK and
the more general Singleton routine.
The _gsl_fft_complex
function is not meant to be called directly;
rather the user should call the fft
function, which provides a
convenient wrapper for the _gsl_fft_complex
function.
Perform an N-d FFT
y = _gsl_fft_complex (x, dir)
This routine computes the FFT of an array x
and returns the
result. The integer-valued parameter dir
parameter specifies
the direction of the transform. A forward transform will be
produced for positive values of dir
and a reverse transform
will be computed for negative values.
The result will be a complex array of the same size and dimensionality as the the input array.
It is better to call this routine indirectly using the fft
function.
Perform an N-d FFT
y = fft (x, dir)
This routine computes the FFT of an array x
and returns the
result. The integer-valued parameter dir
parameter specifies
the direction of the transform. A forward transform will be
produced for positive values of dir
and a reverse transform
will be computed for negative values.
The result will be a complex array of the same size and dimensionality as the the input array.
This routine is currently a wrapper for the _gsl_fft_complex
function.