Mercurial > octave
view scripts/specfun/reallog.m @ 30947:fe898ae23e0e stable
betainc.m: Use sophisticated technique for calculating exponents to avoid innacuracies (bug #62329)
* betainc.m: Use expm1() and log1p() to replace exponentiation operator ".^" in
special case code when a or b equals 1. Add BIST tests for bug #62329.
author | Nir Krakauer <nkrakauer@ccny.cuny.edu> |
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date | Tue, 19 Apr 2022 15:09:27 -0700 |
parents | 796f54d4ddbf |
children | 5d3faba0342e |
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######################################################################## ## ## Copyright (C) 2008-2022 The Octave Project Developers ## ## See the file COPYRIGHT.md in the top-level directory of this ## distribution or <https://octave.org/copyright/>. ## ## 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 ## <https://www.gnu.org/licenses/>. ## ######################################################################## ## -*- texinfo -*- ## @deftypefn {} {} reallog (@var{x}) ## Return the real-valued natural logarithm of each element of @var{x}. ## ## If any element results in a complex return value @code{reallog} aborts and ## issues an error. ## @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 (reallog (1:5), log (1:5)) %!test %! x = rand (10, 10); %! assert (reallog (x), log (x)); %!error <Invalid call> reallog () %!error <produced complex result> reallog (2i) %!error <produced complex result> reallog (-1)