Add a useful package (from Source forge) for octave

[CreaPhase.git] / octave_packages / specfun-1.1.0 / heaviside.m

diff --git a/octave_packages/specfun-1.1.0/heaviside.m b/octave_packages/specfun-1.1.0/heaviside.m
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+## Copyright (C) 2006   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} {} heaviside(@var{x})
+## @deftypefnx{Function File} {} heaviside(@var{x}, @var{zero_value})
+## Compute the Heaviside step function.
+##
+## The Heaviside function is defined as
+##
+## @example
+##   Heaviside (@var{x}) = 1,   @var{x} > 0
+##   Heaviside (@var{x}) = 0,   @var{x} < 0
+## @end example
+##
+## @noindent
+## The value of the Heaviside function at @var{x} = 0 is by default 0.5,
+## but can be changed via the optional second input argument.
+## @seealso{dirac}
+## @end deftypefn
+
+function y = heaviside (x, zero_value = 0.5)
+  if (nargin < 1)
+    print_usage ();
+  endif
+
+  y = cast (x > 0, class (x));
+  y (x == 0) = zero_value;
+endfunction