Mercurial > octave
view scripts/signal/hamming.m @ 21317:a4faec57f4c8
maint: remove semicolon after %!assert tests to follow Octave conventions.
* testfun.txi: Remove semicolons from examples in manual and update remaider
of text to reflect changes.
* bsxfun.cc, cellfun.cc, data.cc, hash.cc, lu.cc, nproc.cc,
rcond.cc, regexp.cc, sparse-xpow.cc, strfns.cc, symtab.cc, time.cc,
variables.cc, ov-class.cc, ov-cx-diag.cc, ov-struct.cc, ov.cc, oct-parse.in.yy,
pt-mat.cc, CMatrix.cc, oct-inttypes.cc, md5sum.m, blkdiag.m, cell2mat.m,
interp1.m, interp2.m, interpft.m, num2str.m, repmat.m, ntsc2rgb.m, expm.m,
inputname.m, polyvalm.m, blackman.m, hamming.m, hanning.m, eigs.m, median.m,
binopdf.m, strsplit.m, strtok.m, assert.m, example.m, datevec.m, bug-38565.tst,
build-sparse-tests.sh, classdef.tst, classes.tst, diag-perm.tst, index.tst,
io.tst, logical-index.tst, nest.tst, parser.tst, prefer.tst, struct.tst:
maint: remove semicolon after %!assert tests to follow Octave conventions.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 21 Feb 2016 08:10:36 -0800 |
parents | 516bb87ea72e |
children | 6fab85c1538f |
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## Copyright (C) 1995-2015 Andreas Weingessel ## ## 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 {} {} hamming (@var{m}) ## @deftypefnx {} {} hamming (@var{m}, "periodic") ## @deftypefnx {} {} hamming (@var{m}, "symmetric") ## Return the filter coefficients of a Hamming window of length @var{m}. ## ## If the optional argument @qcode{"periodic"} is given, the periodic form ## of the window is returned. This is equivalent to the window of length ## @var{m}+1 with the last coefficient removed. The optional argument ## @qcode{"symmetric"} is equivalent to not specifying a second argument. ## ## For a definition of the Hamming window see, e.g., ## @nospell{A.V. Oppenheim & R. W. Schafer}, ## @cite{Discrete-Time Signal Processing}. ## @end deftypefn ## Author: AW <Andreas.Weingessel@ci.tuwien.ac.at> ## Description: Coefficients of the Hamming window function c = hamming (m, opt) if (nargin < 1 || nargin > 2) print_usage (); endif if (! (isscalar (m) && (m == fix (m)) && (m > 0))) error ("hamming: M must be a positive integer"); endif N = m - 1; if (nargin == 2) switch (opt) case "periodic" N = m; case "symmetric" ## Default option, same as no option specified. otherwise error ('hamming: window type must be either "periodic" or "symmetric"'); endswitch endif if (m == 1) c = 1; else m -= 1; c = 0.54 - 0.46 * cos (2 * pi * (0 : m)' / N); endif endfunction %!assert (hamming (1), 1) %!assert (hamming (2), (0.54 - 0.46)*ones (2,1)) %!assert (hamming (15), flip (hamming (15)), 5*eps) %!assert (hamming (16), flip (hamming (16)), 5*eps) %!test %! N = 15; %! A = hamming (N); %! assert (A(ceil (N/2)), 1); %!assert (hamming (15), hamming (15, "symmetric")) %!assert (hamming (16)(1:15), hamming (15, "periodic")) %!test %! N = 16; %! A = hamming (N, "periodic"); %! assert (A(N/2 + 1), 1); %!error hamming () %!error hamming (0.5) %!error hamming (-1) %!error hamming (ones (1,4)) %!error hamming (1, "invalid");