view scripts/specfun/reallog.m @ 16403:1de4ec2a856d

Matlab compatibility for strsplit() * scripts/strings/strsplit.m: Matlab compatible version. * NEWS: Mention break in backward compatibility. * scripts/deprecated/javafields.m: Modify call to strsplit(). * scripts/deprecated/javamethods.m: ditto * scripts/general/fieldnames.m: ditto * scripts/general/int2str.m: ditto * scripts/general/methods.m: ditto * scripts/general/num2str.m: ditto * scripts/help/gen_doc_cache.m: ditto * scripts/help/help.m: ditto * scripts/help/lookfor.m: ditto * scripts/io/strread.m: ditto * scripts/java/javaclasspath.m: ditto * scripts/miscellaneous/compare_versions.m: ditto * scripts/miscellaneous/computer.m: ditto * scripts/miscellaneous/fact.m: ditto * scripts/miscellaneous/tar.m: ditto * scripts/miscellaneous/unpack.m: ditto * scripts/miscellaneous/what.m: ditto * scripts/miscellaneous/zip.m: ditto * scripts/pkg/private/configure_make.m: ditto * scripts/pkg/private/fix_depends.m: ditto * scripts/pkg/private/generate_lookfor_cache.m: ditto * scripts/pkg/private/list_forge_packages.m: ditto * scripts/pkg/private/unload_packages.m: ditto * scripts/pkg/private/write_index.m: ditto * scripts/plot/private/__file_filter__.m: ditto * scripts/plot/private/__fltk_file_filter__.m: ditto * scripts/plot/private/__go_draw_axes__.m: ditto * scripts/plot/private/__next_line_style__.m: ditto * scripts/strings/untabify.m: ditto * scripts/testfun/rundemos.m: ditto * scripts/testfun/runtests.m: ditto
author Ben Abbott <bpabbott@mac.com>
date Sun, 31 Mar 2013 19:19:04 -0400
parents f3d52523cde1
children d63878346099
line wrap: on
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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} {} reallog (@var{x})
## Return the real-valued natural logarithm of each element of @var{x}.  Report
## an error if any element results in a complex return value.
## @seealso{log, realpow, realsqrt}
## @end deftypefn

function y = reallog (x)
  if (nargin != 1)
    print_usage ();
  elseif (iscomplex (x) || any (x(:) < 0))
    error ("reallog: produced complex result");
  else
    y = log (x);
  endif
endfunction


%!assert (log (1:5), reallog (1:5))
%!test
%! x = rand (10,10);
%! assert (log (x),reallog (x));

%!error <produced complex result> reallog (-1)