PermutationMatrixTest.java

package no.uib.cipr.matrix;

import no.uib.cipr.matrix.sparse.CompRowMatrix;
import org.junit.Test;

/**
 * @author Sam Halliday
 */
public class PermutationMatrixTest {

    Matrix m = new DenseMatrix(new double[][]{{2, -1, -2}, {-4, 6, 3},
            {-4, -2, 8}});
    DenseMatrix e = new DenseMatrix(new double[][]{{-4, 6, 3}, {-4, -2, 8},
            {2, -1, -2}});
    DenseMatrix eI = new DenseMatrix(new double[][]{{-4, -2, 8}, {2, -1, -2},
            {-4, 6, 3}});
    int[] piv = new int[]{2, 3, 3};

    @Test
    public void testMultiply() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p
                .mult(m,
                        new CompRowMatrix(new DenseMatrix(m.numRows(), m
                                .numColumns())));
        MatrixTestAbstract.assertMatrixEquals(e, c);
    }

    @Test
    public void testMultiplyTrans() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p
                .transAmult(
                        m,
                        new CompRowMatrix(new DenseMatrix(m.numRows(), m
                                .numColumns())));
        MatrixTestAbstract.assertMatrixEquals(eI, c);
    }

    @Test
    public void testMultiplyDense() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p.mult(m, new DenseMatrix(m.numRows(), m.numColumns()));
        MatrixTestAbstract.assertMatrixEquals(e, c);
    }

    @Test
    public void testMultiplyTransDense() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p
                .transAmult(m, new DenseMatrix(m.numRows(), m.numColumns()));
        MatrixTestAbstract.assertMatrixEquals(eI, c);
    }

    @Test
    public void testMultiplyCompRow() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p.mult(new CompRowMatrix(m), new CompRowMatrix(
                new DenseMatrix(m.numRows(), m.numColumns())));
        MatrixTestAbstract.assertMatrixEquals(e, c);
    }

    @Test
    public void testMultiplyTransCompRow() {
        Matrix p = PermutationMatrix.fromPartialPivots(piv);
        Matrix c = p.transAmult(new CompRowMatrix(m), new CompRowMatrix(
                new DenseMatrix(m.numRows(), m.numColumns())));
        MatrixTestAbstract.assertMatrixEquals(eI, c);
    }

}