Mercurial > octave
view libinterp/corefcn/fft2.cc @ 23433:c9fab0bc983e
maint: Use convention 'int& x' for naming references.
* ButtonGroup.cc, Canvas.cc, Canvas.h, annotation-dialog.cc,
annotation-dialog.h, dialog.h, documentation-dock-widget.cc,
files-dock-widget.cc, files-dock-widget.h, find-files-dialog.cc,
find-files-dialog.h, find-files-model.cc, find-files-model.h,
history-dock-widget.cc, history-dock-widget.h, file-editor-tab.cc,
file-editor-tab.h, file-editor.cc, file-editor.h, main-window.cc,
main-window.h, octave-qt-link.h, parser.cc, parser.h, webinfo.cc, webinfo.h,
settings-dialog.cc, bsxfun.cc, call-stack.cc, call-stack.h, fft.cc, fft2.cc,
fftn.cc, gl-render.cc, graphics.cc, graphics.in.h, input.cc, load-save.cc,
ls-hdf5.cc, ls-hdf5.h, octave-link.h, pr-output.cc, regexp.cc, sparse-xdiv.cc,
sparse-xdiv.h, symtab.cc, xdiv.cc, xdiv.h, zfstream.h, __eigs__.cc,
__ode15__.cc, ov-base.h, ov-builtin.cc, ov-cx-sparse.h, ov-fcn-handle.cc,
ov-fcn-handle.h, ov.cc, ov.h, jit-ir.h, jit-typeinfo.cc, jit-typeinfo.h,
pt-jit.cc, pt-jit.h, CMatrix.cc, CMatrix.h, CSparse.cc, CSparse.h,
MatrixType.cc, MatrixType.h, dDiagMatrix.cc, dMatrix.cc, dMatrix.h, dSparse.cc,
dSparse.h, fCMatrix.cc, fCMatrix.h, fDiagMatrix.cc, fMatrix.cc, fMatrix.h,
eigs-base.cc, oct-fftw.cc, oct-rand.h, sparse-dmsolve.cc, kpse.cc, lo-regexp.h:
Use convention 'int& x' for naming references.
author | Rik <rik@octave.org> |
---|---|
date | Mon, 24 Apr 2017 17:20:37 -0700 |
parents | 092078913d54 |
children | c3075ae020e1 |
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/* Copyright (C) 1997-2017 David Bateman Copyright (C) 1996-1997 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */ #if defined (HAVE_CONFIG_H) # include "config.h" #endif #include "lo-mappers.h" #include "defun.h" #include "error.h" #include "errwarn.h" #include "ovl.h" #include "utils.h" // This function should be merged with Fifft. #if defined (HAVE_FFTW) # define FFTSRC "@sc{fftw}" #else # define FFTSRC "@sc{fftpack}" #endif static octave_value do_fft2 (const octave_value_list& args, const char *fcn, int type) { int nargin = args.length (); if (nargin < 1 || nargin > 3) print_usage (); octave_value retval; octave_value arg = args(0); dim_vector dims = arg.dims (); octave_idx_type n_rows = -1; if (nargin > 1) { double dval = args(1).double_value (); if (octave::math::isnan (dval)) error ("%s: number of rows (N) cannot be NaN", fcn); n_rows = octave::math::nint_big (dval); if (n_rows < 0) error ("%s: number of rows (N) must be greater than zero", fcn); } octave_idx_type n_cols = -1; if (nargin > 2) { double dval = args(2).double_value (); if (octave::math::isnan (dval)) error ("%s: number of columns (M) cannot be NaN", fcn); n_cols = octave::math::nint_big (dval); if (n_cols < 0) error ("%s: number of columns (M) must be greater than zero", fcn); } for (int i = 0; i < dims.ndims (); i++) if (dims(i) < 0) return retval; if (n_rows < 0) n_rows = dims(0); else dims(0) = n_rows; if (n_cols < 0) n_cols = dims(1); else dims(1) = n_cols; if (dims.all_zero () || n_rows == 0 || n_cols == 0) { if (arg.is_single_type ()) return octave_value (FloatMatrix ()); else return octave_value (Matrix ()); } if (arg.is_single_type ()) { if (arg.is_real_type ()) { FloatNDArray nda = arg.float_array_value (); nda.resize (dims, 0.0); retval = (type != 0 ? nda.ifourier2d () : nda.fourier2d ()); } else { FloatComplexNDArray cnda = arg.float_complex_array_value (); cnda.resize (dims, 0.0); retval = (type != 0 ? cnda.ifourier2d () : cnda.fourier2d ()); } } else { if (arg.is_real_type ()) { NDArray nda = arg.array_value (); nda.resize (dims, 0.0); retval = (type != 0 ? nda.ifourier2d () : nda.fourier2d ()); } else if (arg.is_complex_type ()) { ComplexNDArray cnda = arg.complex_array_value (); cnda.resize (dims, 0.0); retval = (type != 0 ? cnda.ifourier2d () : cnda.fourier2d ()); } else err_wrong_type_arg (fcn, arg); } return retval; } DEFUN (fft2, args, , doc: /* -*- texinfo -*- @deftypefn {} {} fft2 (@var{A}) @deftypefnx {} {} fft2 (@var{A}, @var{m}, @var{n}) Compute the two-dimensional discrete Fourier transform of @var{A} using a Fast Fourier Transform (FFT) algorithm. The optional arguments @var{m} and @var{n} may be used specify the number of rows and columns of @var{A} to use. If either of these is larger than the size of @var{A}, @var{A} is resized and padded with zeros. If @var{A} is a multi-dimensional matrix, each two-dimensional sub-matrix of @var{A} is treated separately. @seealso{ifft2, fft, fftn, fftw} @end deftypefn */) { return do_fft2 (args, "fft2", 0); } DEFUN (ifft2, args, , doc: /* -*- texinfo -*- @deftypefn {} {} ifft2 (@var{A}) @deftypefnx {} {} ifft2 (@var{A}, @var{m}, @var{n}) Compute the inverse two-dimensional discrete Fourier transform of @var{A} using a Fast Fourier Transform (FFT) algorithm. The optional arguments @var{m} and @var{n} may be used specify the number of rows and columns of @var{A} to use. If either of these is larger than the size of @var{A}, @var{A} is resized and padded with zeros. If @var{A} is a multi-dimensional matrix, each two-dimensional sub-matrix of @var{A} is treated separately @seealso{fft2, ifft, ifftn, fftw} @end deftypefn */) { return do_fft2 (args, "ifft2", 1); } /* ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!test %! M = 16; %! N = 8; %! %! m = 5; %! n = 3; %! %! x = 2*pi*(0:1:M-1)/M; %! y = 2*pi*(0:1:N-1)/N; %! sx = cos (m*x); %! sy = sin (n*y); %! s = kron (sx',sy); %! S = fft2 (s); %! answer = kron (fft (sx)', fft (sy)); %! assert (S, answer, 4*M*N*eps); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!test %! M = 12; %! N = 7; %! %! m = 3; %! n = 2; %! %! x = 2*pi*(0:1:M-1)/M; %! y = 2*pi*(0:1:N-1)/N; %! %! sx = cos (m*x); %! sy = cos (n*y); %! %! S = kron (fft (sx)', fft (sy)); %! answer = kron (sx', sy); %! s = ifft2 (S); %! %! assert (s, answer, 30*eps); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!test %! M = 16; %! N = 8; %! %! m = 5; %! n = 3; %! %! x = 2*pi*(0:1:M-1)/M; %! y = 2*pi*(0:1:N-1)/N; %! sx = single (cos (m*x)); %! sy = single (sin (n*y)); %! s = kron (sx', sy); %! S = fft2 (s); %! answer = kron (fft (sx)', fft (sy)); %! assert (S, answer, 4*M*N*eps ("single")); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!test %! M = 12; %! N = 7; %! %! m = 3; %! n = 2; %! %! x = single (2*pi*(0:1:M-1)/M); %! y = single (2*pi*(0:1:N-1)/N); %! %! sx = cos (m*x); %! sy = cos (n*y); %! %! S = kron (fft (sx)', fft (sy)); %! answer = kron (sx', sy); %! s = ifft2 (S); %! %! assert (s, answer, 30*eps ("single")); */