Mercurial > octave-nkf
view scripts/ode/private/kahan.m @ 20570:6256f6e366ac
Fix copyright text in private ode functions
* script/ode/private/*.m: Fox the copyright text.
author | Carlo de Falco <carlo.defalco@polimi.it> |
---|---|
date | Fri, 02 Oct 2015 05:50:43 +0200 |
parents | fcb792acab9b |
children | 25623ef2ff4f |
line wrap: on
line source
## Copyright (C) 2013, Roberto Porcu' <roberto.porcu@polimi.it> ## ## 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 {Command} {[@var{sum}] =} kahan (@var{sum}, ## @var{comp}, @var{temp}) ## @deftypefnx {Command} {[@var{sum}, @var{comp}] =} kahan (@var{sum}, ## @var{comp}, @var{temp}) ## ## This function is the implementation of the Kahan summation algorithm, ## also known as compensated summation. It significantly reduces the numerical ## error in the total obtained by adding a sequence of finite precision ## floating point numbers, compared to the obvious approach. For more details ## see @url{http://en.wikipedia.org/wiki/Kahan_summation_algorithm}. ## This function is called in @command{integrate_adaptive} and in ## @command{integrate_const} to better catch equality comparisons. ## ## The first input argument is the variable that will contain the summation, ## so that is also returned as first output argument in order to reuse it in ## next calls to kahan function. ## ## The second input argument contains the compensation term and it is returned ## as second output argument so that it can be reused in the next calls ## of the same computation. ## ## The third input argument is the variable that contains the term to ## be added to @var{Sum}. ## @end deftypefn function [Sum, comp] = kahan (Sum, comp, term) y = term - comp; t = Sum + y; comp = (t - Sum) - y; Sum = t; endfunction ## Local Variables: *** ## mode: octave *** ## End: ***