Add a useful package (from Source forge) for octave

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

diff --git a/octave_packages/signal-1.1.3/mexihat.m b/octave_packages/signal-1.1.3/mexihat.m
new file mode 100644 (file)
index 0000000..410b462
--- /dev/null
+++ b/octave_packages/signal-1.1.3/mexihat.m
@@ -0,0 +1,29 @@
+## 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{psi,x}] =} mexihat(@var{lb,ub,n})
+## Compute the Mexican hat wavelet.
+## @end deftypefn
+
+function [psi,x] = mexihat(lb,ub,n)
+  if (nargin < 3); print_usage; end
+
+  if (n <= 0)
+    error("n must be strictly positive");
+  endif
+  x = linspace(lb,ub,n);
+  psi = (1-x.^2).*(2/(sqrt(3)*pi^0.25)) .* exp(-x.^2/2)  ;
+endfunction