Mercurial > octave
view scripts/signal/spectral_xdf.m @ 21581:6fab85c1538f
maint: Follow Octave conventions for use of semicolon in BIST tests.
* testfun.txi: Document Octave conventions for use of semicolon in BIST tests.
* cellfun.cc, ellipj.cc, file-io.cc, gcd.cc, hash.cc, nproc.cc,
utils.cc, fftw.cc, ov-usr-fcn.cc, oct-parse.in.yy, md5sum.m, wavread.m, wavwrite.m,
cplxpair.m, rat.m, im2double.m, rref.m, stem3.m, rotate.m, pchip.m, blackman.m,
hamming.m, hanning.m, spectral_adf.m, spectral_xdf.m, assert.m, fail.m,
etime.m, build-sparse-tests.sh, classes.tst, ctor-vs-method.tst, index.tst,
io.tst, struct.tst: Follow Octave conventions for use of semicolon in BIST
tests.
author | Rik <rik@octave.org> |
---|---|
date | Fri, 01 Apr 2016 18:16:01 -0700 |
parents | 516bb87ea72e |
children | bac0d6f07a3e |
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## Copyright (C) 1995-2015 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 {} {} spectral_xdf (@var{x}) ## @deftypefnx {} {} spectral_xdf (@var{x}, @var{win}) ## @deftypefnx {} {} 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., @qcode{"triangle"} or @qcode{"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. ## @seealso{spectral_adf} ## @end deftypefn ## Author: FL <Friedrich.Leisch@ci.tuwien.ac.at> ## Description: Spectral density estimation function retval = spectral_xdf (x, win, b) if (nargin < 1 || nargin > 3) print_usage (); endif 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); elseif (! ischar (win)) error ("spectral_xdf: WIN must be a string"); else win = str2func ([win "_sw"]); w = feval (win, xr, b); endif 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 ## Test input validation %!error spectral_xdf () %!error spectral_xdf (1, 2, 3, 4) %!error spectral_xdf (1, 2) %!error spectral_xdf (1, "invalid")