/*
 * Maxima (computer algebra system) configuration file, Maxima part.
 *
 * Also have a look at maxima/maxima-init.lisp.
 *
 * Notes:
 *
 * Solve Ax = b, thanks to Florian.
 *
 * A : matrix([1,2,0],[0,2,3],[0,0,4])$
 * b : matrix([1],[3],[5])$
 * linsolve_by_lu(A,b);
 */

/*
 * Copyright (C) 2011-2012  Simon Ruderich
 *
 * This file 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.
 *
 * This file 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 this file.  If not, see <http://www.gnu.org/licenses/>.
 */


/* CUSTOM FUNCTIONS */

/* Didn't find any euclid norm in Maxima, so here it is. */
norm(x) := sqrt(transpose(x) . x);

/* Maxima's mat_norm() can't calculate the 2-norm. Thanks to Wolfgang Lindner
 * (http://www.ma.utexas.edu/pipermail/maxima/2007/006300.html) for an
 * improved version. */
mat_norm2(x) := sqrt(lmax(eigenvalues(transpose(conjugate(x)) . x)[1]));

/* Shortcut to perform lu factorization. */
lu(x) := block(x : lu_factor(x), get_lu_factors(x));

/* vim: ft=maxima */