Mercurial > octave-nkf
view scripts/polynomial/polyvalm.m @ 20643:d6d04088ac9e
nbininv.m: Increase speed (85X) and accuracy of function (bug #34363).
* nbininv.m: Call new function scalar_nbininv to calculate nbininv for scalar.
If there are still uncalculated values then call bin_search_nbininv. Call
bin_search_nbininv directly for vectors. Add more BIST tests.
* nbininv.m (scalar_binoinv): New subfunction to calculate nbininv for scalar x.
Stops when x > 1000.
* nbininv.m (bin_search_nbininv): New subfunction to do binary search for nbininv.
author | Lachlan Andrew <lachlanbis@gmail.com> |
---|---|
date | Sun, 11 Oct 2015 20:33:37 -0700 |
parents | 4197fc428c7d |
children |
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## Copyright (C) 1994-2015 John W. Eaton ## Copyright (C) 2009 Jaroslav Hajek ## ## 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} {} polyvalm (@var{c}, @var{x}) ## Evaluate a polynomial in the matrix sense. ## ## @code{polyvalm (@var{c}, @var{x})} will evaluate the polynomial in the ## matrix sense, i.e., matrix multiplication is used instead of element by ## element multiplication as used in @code{polyval}. ## ## The argument @var{x} must be a square matrix. ## @seealso{polyval, roots, poly} ## @end deftypefn ## Author: Tony Richardson <arichard@stark.cc.oh.us> ## Created: June 1994 ## Adapted-By: jwe function y = polyvalm (c, x) if (nargin != 2) print_usage (); endif if (! (isvector (c) || isempty (c))) error ("polyvalm: first argument must be a vector"); endif if (! issquare (x)) error ("polyvalm: second argument must be a square matrix"); endif n = length (c); if (n == 0) y = zeros (rows (x), class (x)); else id = eye (rows (x), class (x)); y = c(1) * id; for i = 2:n y = y * x + c(i) * id; endfor endif endfunction %!assert (! any (polyvalm ([], [1, 2; 3, 4]))(:)); %!assert (polyvalm ([1, 2, 3, 4], [3, -4, 1; -2, 0, 2; -1, 4, -3]), [117, -124, 11; -70, 36, 38; -43, 92, -45]) %!error <must be a square matrix> polyvalm ([1, 1, 1], [1, 2; 3, 4; 5, 6])