Mercurial > jwe > octave
view libinterp/corefcn/fft.cc @ 30893:32d2b6604a9f
doc: Ensure documentation lists output argument when it exists for functions in libinterp/
For new users of Octave it is best to show explicit calling forms
in the documentation and to show a return argument when it exists.
* __ftp__.cc, __magick_read__.cc, __pchip_deriv__.cc, bitfcns.cc, bsxfun.cc,
call-stack.cc, cellfun.cc, chol.cc, conv2.cc, data.cc, debug.cc, defaults.cc,
det.cc, dirfns.cc, display.cc, dot.cc, error.cc, event-manager.cc, fft.cc,
fft2.cc, fftn.cc, file-io.cc, getgrent.cc, getpwent.cc, getrusage.cc,
graphics.cc, hash.cc, help.cc, input.cc, interpreter.cc, kron.cc, load-path.cc,
mappers.cc, max.cc, nproc.cc, oct-hist.cc, pager.cc, pinv.cc, psi.cc, rand.cc,
settings.cc, sighandlers.cc, stream-euler.cc, strfns.cc, symtab.cc,
syscalls.cc, sysdep.cc, time.cc, toplev.cc, utils.cc, variables.cc,
__fltk_uigetfile__.cc, audiodevinfo.cc, audioread.cc, fftw.cc, ov-bool-mat.cc,
ov-cell.cc, ov-class.cc, ov-classdef.cc, ov-fcn-handle.cc, ov-java.cc,
ov-struct.cc, ov-typeinfo.cc, ov-usr-fcn.cc, ov.cc, octave.cc, profiler.cc:
Add return arguments to @deftypefn macros where they were missing.
Attempt to use standard naming convention for return variables.
Occasionally improved the docstring itself by re-wording or adding code
examples.
author | Rik <rik@octave.org> |
---|---|
date | Mon, 04 Apr 2022 10:31:48 -0700 |
parents | 796f54d4ddbf |
children |
line wrap: on
line source
//////////////////////////////////////////////////////////////////////// // // 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 static octave_value do_fft (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); octave_idx_type n_points = -1; dim_vector dims = arg.dims (); int ndims = dims.ndims (); int dim = -1; if (nargin > 1) { if (! args(1).isempty ()) { double dval = args(1).double_value (); if (math::isnan (dval)) error ("%s: number of points (N) cannot be NaN", fcn); n_points = math::nint_big (dval); if (n_points < 0) error ("%s: number of points (N) must be greater than zero", fcn); } } if (nargin > 2) { double dval = args(2).double_value (); if (math::isnan (dval)) error ("%s: DIM cannot be NaN", fcn); else if (dval < 1 || dval > ndims) error ("%s: DIM must be a valid dimension along which to perform FFT", fcn); else // to be safe, cast it back to int since dim is an int dim = math::nint (dval) - 1; } // FIXME: This seems strange and unnecessary (10/21/16). // How would you ever arrive at an octave_value object without correct dims? // We certainly don't make this check every other place in Octave. for (octave_idx_type i = 0; i < ndims; i++) if (dims(i) < 0) return retval; if (dim < 0) { dim = dims.first_non_singleton (); // And if the first argument is scalar? if (dim == ndims) dim = 1; } if (n_points < 0) n_points = dims(dim); else dims(dim) = n_points; if (n_points == 0 || dims.any_zero ()) { if (arg.is_single_type ()) return octave_value (FloatNDArray (dims)); else return octave_value (NDArray (dims)); } if (n_points == 1) { octave_value_list idx (ndims); for (octave_idx_type i = 0; i < ndims; i++) idx(i) = idx_vector::colon; idx(dim) = idx_vector (0); return arg.index_op (idx); } if (arg.is_single_type ()) { if (arg.isreal ()) { FloatNDArray nda = arg.float_array_value (); nda.resize (dims, 0.0); retval = (type != 0 ? nda.ifourier (dim) : nda.fourier (dim)); } else { FloatComplexNDArray cnda = arg.float_complex_array_value (); cnda.resize (dims, 0.0); retval = (type != 0 ? cnda.ifourier (dim) : cnda.fourier (dim)); } } else { if (arg.isreal ()) { NDArray nda = arg.array_value (); nda.resize (dims, 0.0); retval = (type != 0 ? nda.ifourier (dim) : nda.fourier (dim)); } else if (arg.iscomplex ()) { ComplexNDArray cnda = arg.complex_array_value (); cnda.resize (dims, 0.0); retval = (type != 0 ? cnda.ifourier (dim) : cnda.fourier (dim)); } else err_wrong_type_arg (fcn, arg); } return retval; } /* %!testif HAVE_FFTW %! assert (fft ([]), []) %!testif HAVE_FFTW %! assert (fft (zeros (10,0)), zeros (10,0)) %!testif HAVE_FFTW %! assert (fft (zeros (0,10)), zeros (0,10)) %!testif HAVE_FFTW %! assert (fft (0), 0) %!testif HAVE_FFTW %! assert (fft (1), 1) %!testif HAVE_FFTW %! assert (fft (ones (2,2)), [2,2; 0,0]) %!testif HAVE_FFTW %! assert (fft (eye (2,2)), [1,1; 1,-1]) %!testif HAVE_FFTW %! assert (fft (single ([])), single ([])) %!testif HAVE_FFTW %! assert (fft (zeros (10,0,"single")), zeros (10,0,"single")) %!testif HAVE_FFTW %! assert (fft (zeros (0,10,"single")), zeros (0,10,"single")) %!testif HAVE_FFTW %! assert (fft (single (0)), single (0)) %!testif HAVE_FFTW %! assert (fft (single (1)), single (1)) %!testif HAVE_FFTW %! assert (fft (ones (2,2,"single")), single ([2,2; 0,0])) %!testif HAVE_FFTW %! assert (fft (eye (2,2,"single")), single ([1,1; 1,-1])) %!error fft () */ DEFUN (fft, args, , doc: /* -*- texinfo -*- @deftypefn {} {@var{y} =} fft (@var{x}) @deftypefnx {} {@var{y} =} fft (@var{x}, @var{n}) @deftypefnx {} {@var{y} =} fft (@var{x}, @var{n}, @var{dim}) Compute the discrete Fourier transform of @var{x} using a Fast Fourier Transform (FFT) algorithm. The FFT is calculated along the first non-singleton dimension of the array. Thus if @var{x} is a matrix, @code{fft (@var{x})} computes the FFT for each column of @var{x}. If called with two arguments, @var{n} is expected to be an integer specifying the number of elements of @var{x} to use, or an empty matrix to specify that its value should be ignored. If @var{n} is larger than the dimension along which the FFT is calculated, then @var{x} is resized and padded with zeros. Otherwise, if @var{n} is smaller than the dimension along which the FFT is calculated, then @var{x} is truncated. If called with three arguments, @var{dim} is an integer specifying the dimension of the matrix along which the FFT is performed. @seealso{ifft, fft2, fftn, fftw} @end deftypefn */) { return do_fft (args, "fft", 0); } DEFUN (ifft, args, , doc: /* -*- texinfo -*- @deftypefn {} {@var{x} =} ifft (@var{y}) @deftypefnx {} {@var{x} =} ifft (@var{y}, @var{n}) @deftypefnx {} {@var{x} =} ifft (@var{y}, @var{n}, @var{dim}) Compute the inverse discrete Fourier transform of @var{y} using a Fast Fourier Transform (FFT) algorithm. The inverse FFT is calculated along the first non-singleton dimension of the array. Thus if @var{y} is a matrix, @code{ifft (@var{y})} computes the inverse FFT for each column of @var{y}. If called with two arguments, @var{n} is expected to be an integer specifying the number of elements of @var{y} to use, or an empty matrix to specify that its value should be ignored. If @var{n} is larger than the dimension along which the inverse FFT is calculated, then @var{y} is resized and padded with zeros. Otherwise, if @var{n} is smaller than the dimension along which the inverse FFT is calculated, then @var{y} is truncated. If called with three arguments, @var{dim} is an integer specifying the dimension of the matrix along which the inverse FFT is performed. @seealso{fft, ifft2, ifftn, fftw} @end deftypefn */) { return do_fft (args, "ifft", 1); } /* ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!testif HAVE_FFTW %! N = 64; %! n = 4; %! t = 2*pi*(0:1:N-1)/N; %! s = cos (n*t); %! S = fft (s); %! %! answer = zeros (size (t)); %! answer(n+1) = N/2; %! answer(N-n+1) = N/2; %! %! assert (S, answer, 4*N*eps); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!testif HAVE_FFTW %! N = 64; %! n = 7; %! t = 2*pi*(0:1:N-1)/N; %! s = cos (n*t); %! %! S = zeros (size (t)); %! S(n+1) = N/2; %! S(N-n+1) = N/2; %! %! assert (ifft (S), s, 4*N*eps); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!testif HAVE_FFTW %! N = 64; %! n = 4; %! t = single (2*pi*(0:1:N-1)/N); %! s = cos (n*t); %! S = fft (s); %! %! answer = zeros (size (t), "single"); %! answer(n+1) = N/2; %! answer(N-n+1) = N/2; %! %! assert (S, answer, 4*N*eps ("single")); ## Author: David Billinghurst (David.Billinghurst@riotinto.com.au) ## Comalco Research and Technology ## 02 May 2000 %!testif HAVE_FFTW %! N = 64; %! n = 7; %! t = 2*pi*(0:1:N-1)/N; %! s = cos (n*t); %! %! S = zeros (size (t), "single"); %! S(n+1) = N/2; %! S(N-n+1) = N/2; %! %! assert (ifft (S), s, 4*N*eps ("single")); */ OCTAVE_NAMESPACE_END