/*
* Copyright (c) 2009-2012, Peter Abeles. All Rights Reserved.
*
* This file is part of Efficient Java Matrix Library (EJML).
*
* EJML is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3
* of the License, or (at your option) any later version.
*
* EJML 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EJML. If not, see <http://www.gnu.org/licenses/>.
*/
package org.ejml.alg.dense.linsol;
import org.ejml.alg.dense.decomposition.lu.LUDecompositionAlt;
import org.ejml.alg.dense.linsol.lu.LinearSolverLu;
import org.ejml.data.DenseMatrix64F;
import org.ejml.factory.LinearSolver;
import org.ejml.ops.CommonOps;
import org.ejml.ops.RandomMatrices;
import org.junit.Test;
import java.util.Random;
import static org.junit.Assert.assertEquals;
/**
* @author Peter Abeles
*/
public class TestInvertUsingSolve {
Random rand = new Random(0xff);
double tol = 1e-8;
/**
* See if it can invert a matrix that is known to be invertable.
*/
@Test
public void invert() {
DenseMatrix64F A = new DenseMatrix64F(3,3, true, 0, 1, 2, -2, 4, 9, 0.5, 0, 5);
DenseMatrix64F A_inv = RandomMatrices.createRandom(3,3,rand);
LUDecompositionAlt decomp = new LUDecompositionAlt();
LinearSolver solver = new LinearSolverLu(decomp);
solver.setA(A);
InvertUsingSolve.invert(solver,A,A_inv);
DenseMatrix64F I = RandomMatrices.createRandom(3,3,rand);
CommonOps.mult(A,A_inv,I);
for( int i = 0; i < I.numRows; i++ ) {
for( int j = 0; j < I.numCols; j++ ) {
if( i == j )
assertEquals(1,I.get(i,j),tol);
else
assertEquals(0,I.get(i,j),tol);
}
}
}
}