/*
* Encog(tm) Core v3.4 - Java Version
* http://www.heatonresearch.com/encog/
* https://github.com/encog/encog-java-core
* Copyright 2008-2016 Heaton Research, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* For more information on Heaton Research copyrights, licenses
* and trademarks visit:
* http://www.heatonresearch.com/copyright
*/
package org.encog.mathutil.matrices.decomposition;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import org.encog.mathutil.matrices.Matrix;
import org.junit.Test;
/**
* Simple tests for the EigenvalueDecomposition object.
*/
public class EigenvalueDecompositionTest {
private Matrix matrix1 = new Matrix(
new double[][] {
{ 2.0, 5.1 },
{ -0.5, 0.9 }
});
private Matrix matrix2 = new Matrix(
new double[][] {
{ 2.0, 5.5 },
{ 5.5, -1.0 }
});
@Test
public void testEigenvalueDecomposition() {
new EigenvalueDecomposition(matrix1);
}
@Test
public void testGetD_asymentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix1);
Matrix d = decomposition.getD();
assertEquals(2, d.getCols());
assertEquals(2, d.getRows());
assertEquals(1.45, d.get(0, 0), 1e-10);
assertEquals(1.4991664351, d.get(0, 1), 1e-10);
assertEquals(-1.4991664351, d.get(1, 0), 1e-10);
assertEquals(1.45, d.get(1, 1), 1e-10);
}
@Test
public void testGetD_symentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix2);
Matrix d = decomposition.getD();
assertEquals(2, d.getCols());
assertEquals(2, d.getRows());
assertEquals(-5.2008771255, d.get(0, 0), 1e-10);
assertEquals(0.0, d.get(0, 1), 1e-10);
assertEquals(0.0, d.get(1, 0), 1e-10);
assertEquals(6.2008771255, d.get(1, 1), 1e-10);
}
@Test
public void testGetImagEigenvalues_asymentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix1);
double[] d = decomposition.getImagEigenvalues();
assertEquals(2, d.length);
assertEquals(1.4991664351, d[0], 1e-10);
assertEquals(-1.4991664351, d[1], 1e-10);
}
@Test
public void testGetImagEigenvalues_symentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix2);
double[] d = decomposition.getImagEigenvalues();
assertEquals(2, d.length);
assertEquals(0.0, d[0], 1e-10);
assertEquals(0.0, d[1], 1e-10);
}
@Test
public void testGetRealEigenvalues_asymentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix1);
double[] d = decomposition.getRealEigenvalues();
assertEquals(2, d.length);
assertEquals(1.45, d[0], 1e-10);
assertEquals(1.45, d[1], 1e-10);
}
@Test
public void testGetRealEigenvalues_symentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix2);
double[] d = decomposition.getRealEigenvalues();
assertEquals(2, d.length);
assertEquals(-5.2008771255, d[0], 1e-10);
assertEquals(6.2008771255, d[1], 1e-10);
}
@Test
public void testGetV_asymentric() {
EigenvalueDecomposition decomposition =
new EigenvalueDecomposition(matrix1);
Matrix d = decomposition.getV();
assertEquals(2, d.getCols());
assertEquals(2, d.getRows());
assertEquals(2.9983328701, d.get(0, 0), 1e-10);
assertEquals(-1.1, d.get(0, 1), 1e-10);
assertEquals(0.0, d.get(1, 0), 1e-10);
assertEquals(1.0, d.get(1, 1), 1e-10);
}
@Test
public void testIsSymmetric() {
assertTrue(
"An empty matrix should be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] { }));
assertFalse(
"An matrix with a row but no values should not be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] { { } }));
assertTrue(
"A singleton matrix should be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] { { 0 } }));
assertFalse(
"A malformed matrix should not be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] {
{ 0, 1 }
}));
assertTrue(
"This simple matrix should be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] {
{ 0, 1 },
{ 1, 0 },
}));
assertFalse(
"This simple matrix should not be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] {
{ 0, 1 },
{ 2, 0 },
}));
assertTrue(
"This matrix should be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] {
{ 0, 1, 3, 8 },
{ 1, 5, 7, 1 },
{ 3, 7, 9, 0 },
{ 8, 1, 0, 6 },
}));
assertFalse(
"This matrix should not be symmetric",
EigenvalueDecomposition.isSymmetric(new double[][] {
{ 8, 1, 0, 6 },
{ 3, 7, 9, 0 },
{ 1, 5, 7, 1 },
{ 0, 1, 3, 8 },
}));
}
}