Mercurial > octave-nkf
view scripts/special-matrix/wilkinson.m @ 7016:93c65f2a5668
[project @ 2007-10-12 06:40:56 by jwe]
author | jwe |
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date | Fri, 12 Oct 2007 06:41:26 +0000 |
parents | 1fe78adb91bc |
children | a1dbe9d80eee |
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## Copyright (C) 1999 Peter Ekberg ## ## 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} {} wilkinson (@var{n}) ## ## Return the Wilkinson matrix of order @var{n}. ## ## @seealso{hankel, vander, sylvester_matrix, hilb, invhilb, toeplitz ## hadamard, rosser, compan, pascal} ## @end deftypefn ## Author: Peter Ekberg ## (peda) function retval = wilkinson (n) if (nargin != 1) print_usage (); endif nmax = length (n); if (! (nmax == 1)) error ("wilkinson: expecting scalar argument, found something else"); endif side = ones (n-1, 1); center = abs (-(n-1)/2:(n-1)/2); retval = diag (side, -1) + diag (center) + diag (side, 1); endfunction