Mercurial > hg > octave-lyh
diff scripts/specfun/realpow.m @ 7621:4682dda22527
Add the reallog, realsqrt and realpow functions
author | David Bateman <dbateman@free.fr> |
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date | Fri, 21 Mar 2008 16:09:01 +0100 |
parents | |
children | 23c248d415b5 |
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new file mode 100644 --- /dev/null +++ b/scripts/specfun/realpow.m @@ -0,0 +1,45 @@ +## Copyright (C) 2008 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}) +## Return the element by element power operator. This is equivalent to +## @code{@var{x} .^ @var{y}), except that if the return value +## is complex @code{realpow} produces an error. +## @seealso{log, 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))