Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/signal-1.1.3/diric.m b/octave_packages/signal-1.1.3/diric.m
new file mode 100644 (file)
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+++ b/octave_packages/signal-1.1.3/diric.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{y}] =} diric(@var{x},@var{n})
+## Compute the dirichlet function.
+## @seealso{sinc,  gauspuls, sawtooth}
+## @end deftypefn
+
+function [y] = diric(x,n)
+  if (nargin < 2)
+    print_usage;
+  elseif (n <= 0 || floor(n) ~= n)
+    error("n must be an integer strictly positive");
+  endif
+
+  y = sin(n.*x./2)./(n.*sin(x./2));
+  y(mod(x,2*pi)==0) = (-1).^((n-1).*x(mod(x,2*pi)==0)./(2.*pi));
+
+endfunction