Mercurial > octave-libtiff
view libinterp/corefcn/fft2.cc @ 31193:c142c153034c
Tiff: implemented imwrite handler that uses the Tiff interface
* __tiff__.cc (F__tiff_imwrite__): implemented internal function to
act as imwrite handler for tiff images but uses the new Tiff interface.
author | magedrifaat <magedrifaat@gmail.com> |
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date | Sat, 27 Aug 2022 23:06:54 +0200 |
parents | 32d2b6604a9f |
children |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 1996-2022 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // 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 // <https://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" OCTAVE_NAMESPACE_BEGIN // This function should be merged with Fifft. 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 (math::isnan (dval)) error ("%s: number of rows (N) cannot be NaN", fcn); n_rows = 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 (math::isnan (dval)) error ("%s: number of columns (M) cannot be NaN", fcn); n_cols = 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.isreal ()) { 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.isreal ()) { NDArray nda = arg.array_value (); nda.resize (dims, 0.0); retval = (type != 0 ? nda.ifourier2d () : nda.fourier2d ()); } else if (arg.iscomplex ()) { 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 {} {@var{B} =} fft2 (@var{A}) @deftypefnx {} {@var{B} =} 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 {} {@var{A} =} ifft2 (@var{B}) @deftypefnx {} {@var{A} =} ifft2 (@var{B}, @var{m}, @var{n}) Compute the inverse two-dimensional discrete Fourier transform of @var{B} 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{B} to use. If either of these is larger than the size of @var{B}, @var{B} is resized and padded with zeros. If @var{B} is a multi-dimensional matrix, each two-dimensional sub-matrix of @var{B} 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 %!testif HAVE_FFTW %! 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 %!testif HAVE_FFTW %! 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 %!testif HAVE_FFTW %! 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 %!testif HAVE_FFTW %! 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")); */ OCTAVE_NAMESPACE_END