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fft.cc
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1996-11-03
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/*
Copyright (C) 1996 John W. Eaton
This file is part of Octave.
Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.
Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "help.h"
#include "mappers.h"
#include "oct-obj.h"
#include "utils.h"
// This function should be merged with Fifft.
DEFUN_DLD (fft, args, ,
"fft (X [, N]): fast fourier transform of a vector")
{
octave_value_list retval;
int nargin = args.length ();
if (nargin < 1 || nargin > 2)
{
print_usage ("fft");
return retval;
}
octave_value arg = args(0);
int n_points = arg.rows ();
if (n_points == 1)
n_points = arg.columns ();
if (nargin == 2)
{
double dval = args(1).double_value ();
if (xisnan (dval))
error ("fft: NaN is invalid as the N_POINTS");
else
n_points = NINT (dval);
}
if (error_state)
return retval;
if (n_points < 0)
{
error ("fft: number of points must be greater than zero");
return retval;
}
int arg_is_empty = empty_arg ("fft", arg.rows (), arg.columns ());
if (arg_is_empty < 0)
return retval;
else if (arg_is_empty || n_points == 0)
return Matrix ();
if (arg.is_real_type ())
{
Matrix m = arg.matrix_value ();
if (! error_state)
{
if (m.rows () == 1)
m.resize (1, n_points, 0.0);
else
m.resize (n_points, m.columns (), 0.0);
retval = m.fourier ();
}
}
else if (arg.is_complex_type ())
{
ComplexMatrix m = arg.complex_matrix_value ();
if (! error_state)
{
if (m.rows () == 1)
m.resize (1, n_points, 0.0);
else
m.resize (n_points, m.columns (), 0.0);
retval = m.fourier ();
}
}
else
{
gripe_wrong_type_arg ("fft", arg);
}
return retval;
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/