update packages

[CreaPhase.git] / octave_packages / m / strings / isletter.m

diff --git a/octave_packages/m/strings/isletter.m b/octave_packages/m/strings/isletter.m
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+++ b/octave_packages/m/strings/isletter.m
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+## Copyright (C) 1998-2012 John W. Eaton
+##
+## This file is part of Octave.
+##
+## Octave 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.
+##
+## Octave 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 Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} isletter (@var{s})
+## Return a logical array which is true where the elements of @var{s}
+## are letters and false where they are not.  This is an alias for
+## the @code{isalpha} function.
+## @seealso{isalpha, isdigit, ispunct, isspace, iscntrl, isalnum}
+## @end deftypefn
+
+## Author: jwe
+
+function retval = isletter (s)
+
+  if (nargin != 1)
+    print_usage ();
+  endif
+
+  retval = isalpha (s);
+
+endfunction
+
+%!error isletter();
+%!error isletter("a", "b");