Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/signal-1.1.3/parzenwin.m b/octave_packages/signal-1.1.3/parzenwin.m
new file mode 100644 (file)
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+++ b/octave_packages/signal-1.1.3/parzenwin.m
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+## Copyright (C) 2007 Sylvain Pelissier <sylvain.pelissier@gmail.com>
+##
+## 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/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {[@var{w}] =} parzenwin(@var{L})
+## Compute the Parzen window of lenght L.
+## @seealso{rectwin,  bartlett}
+## @end deftypefn
+
+function w = parzenwin (L)
+  if(nargin != 1)
+    print_usage;
+  elseif(L < 0)
+    error('L must be positive');
+  end
+
+  if(L ~= floor(L))
+    L = round(L);
+  end
+
+  N = L-1;
+  n = -(N/2):N/2;
+  n1 = n(find(abs(n) <= N/4));
+  n2 = n(find(n > N/4));
+  n3 = n(find(n < -N/4));
+
+  w1 = 1 -6.*(abs(n1)./(L/2)).^2 + 6*(abs(n1)./(L/2)).^3;
+  w2 = 2.*(1-abs(n2)./(L/2)).^3;
+  w3 = 2.*(1-abs(n3)./(L/2)).^3;
+  w = [w3 w1 w2]';
+endfunction