Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / signal-1.1.3 / gaussian.m

diff --git a/octave_packages/signal-1.1.3/gaussian.m b/octave_packages/signal-1.1.3/gaussian.m
new file mode 100644 (file)
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+++ b/octave_packages/signal-1.1.3/gaussian.m
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+## Copyright (C) 1999 Paul Kienzle <pkienzle@users.sf.net>
+##
+## This program 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.
+##
+## This program 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
+## this program; if not, see <http://www.gnu.org/licenses/>.
+
+## usage: w = gaussian(n, a)
+##
+## Generate an n-point gaussian convolution window of the given
+## width.  Use larger a for a narrower window.  Use larger n for
+## longer tails.
+##
+##     w = exp ( -(a*x)^2/2 )
+##
+## for x = linspace ( -(n-1)/2, (n-1)/2, n ).
+##
+## Width a is measured in frequency units (sample rate/num samples). 
+## It should be f when multiplying in the time domain, but 1/f when 
+## multiplying in the frequency domain (for use in convolutions).
+
+function x = gaussian(n, w)
+
+  if nargin < 1 || nargin > 2
+    print_usage;
+  end
+  if nargin == 1, w = 1; endif
+  x = exp(-0.5*(([0:n-1]'-(n-1)/2)*w).^2);
+
+endfunction