update packages

[CreaPhase.git] / octave_packages / m / specfun / realpow.m

diff --git a/octave_packages/m/specfun/realpow.m b/octave_packages/m/specfun/realpow.m
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+## Copyright (C) 2008-2012 David Bateman
+##
+## 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} {} realpow (@var{x}, @var{y})
+## Compute the real-valued, element-by-element power operator.  This is
+## equivalent to @w{@code{@var{x} .^ @var{y}}}, except that @code{realpow}
+## reports an error if any return value is complex.
+## @seealso{reallog, realsqrt}
+## @end deftypefn
+
+function z = realpow (x, y)
+  if (nargin != 2)
+    print_usage ();
+  else
+    z = x .^ y;
+    if (iscomplex (z))
+      error ("realpow: produced complex result");
+    endif
+  endif
+endfunction
+
+%!assert (power (1:10, 0.5:0.5:5), realpow (1:10, 0.5:0.5:5))
+%!assert ([1:10] .^ [0.5:0.5:5], realpow (1:10, 0.5:0.5:5))
+%!test
+%! x = rand (10,10);
+%! y = randn (10,10);
+%! assert (x.^y,realpow(x,y))
+%!assert (realpow(1i,2),-1)
+%!error (realpow(-1, 1/2))