1 ## Copyright (C) 1999 Paul Kienzle <pkienzle@users.sf.net>
3 ## This program is free software; you can redistribute it and/or modify it under
4 ## the terms of the GNU General Public License as published by the Free Software
5 ## Foundation; either version 3 of the License, or (at your option) any later
8 ## This program is distributed in the hope that it will be useful, but WITHOUT
9 ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13 ## You should have received a copy of the GNU General Public License along with
14 ## this program; if not, see <http://www.gnu.org/licenses/>.
16 ## usage: w = gaussian(n, a)
18 ## Generate an n-point gaussian convolution window of the given
19 ## width. Use larger a for a narrower window. Use larger n for
22 ## w = exp ( -(a*x)^2/2 )
24 ## for x = linspace ( -(n-1)/2, (n-1)/2, n ).
26 ## Width a is measured in frequency units (sample rate/num samples).
27 ## It should be f when multiplying in the time domain, but 1/f when
28 ## multiplying in the frequency domain (for use in convolutions).
30 function x = gaussian(n, w)
32 if nargin < 1 || nargin > 2
35 if nargin == 1, w = 1; endif
36 x = exp(-0.5*(([0:n-1]'-(n-1)/2)*w).^2);