Mercurial > octave-nkf
view scripts/signal/spectral_xdf.m @ 16994:333243133364
Use matrix concatenation for strings, rather than cstrcat(), for clarity and performance.
matrix concatenation is ~80% faster than cstrcat().
* doc/interpreter/strings.txi: Document preference for matrix concatenation
as opposed to alternatives.
* doc/interpreter/geometryimages.m, doc/interpreter/interpimages.m,
doc/interpreter/plotimages.m, doc/interpreter/sparseimages.m,
doc/interpreter/splineimages.m, scripts/general/genvarname.m,
scripts/general/int2str.m, scripts/general/num2str.m,
scripts/help/__makeinfo__.m, scripts/help/help.m,
scripts/miscellaneous/copyfile.m, scripts/miscellaneous/dir.m,
scripts/miscellaneous/edit.m, scripts/miscellaneous/fact.m,
scripts/miscellaneous/fullfile.m, scripts/miscellaneous/mkoctfile.m,
scripts/miscellaneous/movefile.m, scripts/miscellaneous/perl.m,
scripts/miscellaneous/python.m, scripts/miscellaneous/run.m,
scripts/miscellaneous/tempdir.m, scripts/miscellaneous/unpack.m,
scripts/pkg/private/configure_make.m, scripts/pkg/private/create_pkgadddel.m,
scripts/pkg/private/extract_pkg.m, scripts/pkg/private/get_description.m,
scripts/pkg/private/get_forge_pkg.m, scripts/pkg/private/getarch.m,
scripts/pkg/private/getarchprefix.m, scripts/pkg/private/install.m,
scripts/pkg/private/installed_packages.m,
scripts/pkg/private/load_packages_and_dependencies.m,
scripts/pkg/private/rebuild.m, scripts/pkg/private/repackage.m,
scripts/pkg/private/shell.m, scripts/pkg/private/uninstall.m,
scripts/plot/private/__go_draw_axes__.m, scripts/signal/spectral_adf.m,
scripts/signal/spectral_xdf.m, scripts/statistics/tests/z_test.m,
scripts/statistics/tests/z_test_2.m, scripts/strings/mat2str.m,
scripts/strings/strtok.m, scripts/testfun/__run_test_suite__.m,
scripts/testfun/assert.m, scripts/testfun/demo.m, scripts/testfun/speed.m,
scripts/testfun/test.m, test/eval-catch.tst, test/io.tst, test/try.tst: Replace
cstrcat() with matrix concatenation where possible.
author | Rik <rik@octave.org> |
---|---|
date | Wed, 17 Jul 2013 14:02:32 -0700 |
parents | 5d3a684236b0 |
children | 2736bc7bf8d9 |
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## Copyright (C) 1995-2012 Friedrich Leisch ## ## 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/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} spectral_xdf (@var{x}, @var{win}, @var{b}) ## Return the spectral density estimator given a data vector @var{x}, ## window name @var{win}, and bandwidth, @var{b}. ## ## The window name, e.g., @code{"triangle"} or @code{"rectangle"} is ## used to search for a function called @code{@var{win}_sw}. ## ## If @var{win} is omitted, the triangle window is used. If @var{b} is ## omitted, @code{1 / sqrt (length (@var{x}))} is used. ## @end deftypefn ## Author: FL <Friedrich.Leisch@ci.tuwien.ac.at> ## Description: Spectral density estimation function retval = spectral_xdf (x, win, b) xr = length (x); if (columns (x) > 1) x = x'; endif if (nargin < 3) b = 1 / ceil (sqrt (xr)); endif if (nargin == 1) w = triangle_sw (xr, b); else win = str2func ([win "_sw")]; w = feval (win, xr, b); endif x = x - sum (x) / xr; retval = (abs (fft (x)) / xr).^2; retval = real (ifft (fft (retval) .* fft (w))); retval = [(zeros (xr, 1)), retval]; retval(:, 1) = (0 : xr-1)' / xr; endfunction