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+## Copyright (C) 2007 Michel D. Schmid <michaelschmid@users.sourceforge.net>
+##
+##
+## 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 2, 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; see the file COPYING. If not, write to the Free
+## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+## 02110-1301, USA.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {}[@var{a} = dsatlin (@var{n})
+##
+## @end deftypefn
+
+## @seealso{dpurelin,dtansig,dlogsig}
+
+## Author: Michel D. Schmid
+
+
+function a = dsatlin(n)
+
+
+ # the derivative of satlin is easy:
+ # where satlin is constant, the derivative is 0
+ # else, because without variable n, the derivative is 1
+ if (n>=0 && n<=1)
+ a = 1;
+ else
+ a = 0;
+ endif
+
+endfunction
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