/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.commons.math.linear;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import org.apache.commons.math.TestUtils;

/**
 * Test cases for the {@link Array2DRowRealMatrix} class.
 *
 * @version $Revision$ $Date$
 */

public final class Array2DRowRealMatrixTest extends TestCase {

	// 3 x 3 identity matrix
	protected double[][] id = { { 1d, 0d, 0d }, { 0d, 1d, 0d }, { 0d, 0d, 1d } };

	// Test data for group operations
	protected double[][] testData = { { 1d, 2d, 3d }, { 2d, 5d, 3d }, { 1d, 0d, 8d } };
	protected double[][] testDataLU = { { 2d, 5d, 3d }, { .5d, -2.5d, 6.5d }, { 0.5d, 0.2d, .2d } };
	protected double[][] testDataPlus2 = { { 3d, 4d, 5d }, { 4d, 7d, 5d }, { 3d, 2d, 10d } };
	protected double[][] testDataMinus = { { -1d, -2d, -3d }, { -2d, -5d, -3d }, { -1d, 0d, -8d } };
	protected double[] testDataRow1 = { 1d, 2d, 3d };
	protected double[] testDataCol3 = { 3d, 3d, 8d };
	protected double[][] testDataInv = { { -40d, 16d, 9d }, { 13d, -5d, -3d }, { 5d, -2d, -1d } };
	protected double[] preMultTest = { 8, 12, 33 };
	protected double[][] testData2 = { { 1d, 2d, 3d }, { 2d, 5d, 3d } };
	protected double[][] testData2T = { { 1d, 2d }, { 2d, 5d }, { 3d, 3d } };
	protected double[][] testDataPlusInv = { { -39d, 18d, 12d }, { 15d, 0d, 0d }, { 6d, -2d, 7d } };

	// lu decomposition tests
	protected double[][] luData = { { 2d, 3d, 3d }, { 0d, 5d, 7d }, { 6d, 9d, 8d } };
	protected double[][] luDataLUDecomposition = { { 6d, 9d, 8d }, { 0d, 5d, 7d },
			{ 0.33333333333333, 0d, 0.33333333333333 } };

	// singular matrices
	protected double[][] singular = { { 2d, 3d }, { 2d, 3d } };
	protected double[][] bigSingular = { { 1d, 2d, 3d, 4d }, { 2d, 5d, 3d, 4d }, { 7d, 3d, 256d, 1930d },
			{ 3d, 7d, 6d, 8d } }; // 4th row = 1st + 2nd
	protected double[][] detData = { { 1d, 2d, 3d }, { 4d, 5d, 6d }, { 7d, 8d, 10d } };
	protected double[][] detData2 = { { 1d, 3d }, { 2d, 4d } };

	// vectors
	protected double[] testVector = { 1, 2, 3 };
	protected double[] testVector2 = { 1, 2, 3, 4 };

	// submatrix accessor tests
	protected double[][] subTestData = { { 1, 2, 3, 4 }, { 1.5, 2.5, 3.5, 4.5 }, { 2, 4, 6, 8 }, { 4, 5, 6, 7 } };
	// array selections
	protected double[][] subRows02Cols13 = { { 2, 4 }, { 4, 8 } };
	protected double[][] subRows03Cols12 = { { 2, 3 }, { 5, 6 } };
	protected double[][] subRows03Cols123 = { { 2, 3, 4 }, { 5, 6, 7 } };
	// effective permutations
	protected double[][] subRows20Cols123 = { { 4, 6, 8 }, { 2, 3, 4 } };
	protected double[][] subRows31Cols31 = { { 7, 5 }, { 4.5, 2.5 } };
	// contiguous ranges
	protected double[][] subRows01Cols23 = { { 3, 4 }, { 3.5, 4.5 } };
	protected double[][] subRows23Cols00 = { { 2 }, { 4 } };
	protected double[][] subRows00Cols33 = { { 4 } };
	// row matrices
	protected double[][] subRow0 = { { 1, 2, 3, 4 } };
	protected double[][] subRow3 = { { 4, 5, 6, 7 } };
	// column matrices
	protected double[][] subColumn1 = { { 2 }, { 2.5 }, { 4 }, { 5 } };
	protected double[][] subColumn3 = { { 4 }, { 4.5 }, { 8 }, { 7 } };

	// tolerances
	protected double entryTolerance = 10E-16;
	protected double normTolerance = 10E-14;

	public Array2DRowRealMatrixTest(String name) {
		super(name);
	}

	public static Test suite() {
		TestSuite suite = new TestSuite(Array2DRowRealMatrixTest.class);
		suite.setName("Array2DRowRealMatrix Tests");
		return suite;
	}

	/** test dimensions */
	public void testDimensions() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testData2);
		assertEquals("testData row dimension", 3, m.getRowDimension());
		assertEquals("testData column dimension", 3, m.getColumnDimension());
		assertTrue("testData is square", m.isSquare());
		assertEquals("testData2 row dimension", m2.getRowDimension(), 2);
		assertEquals("testData2 column dimension", m2.getColumnDimension(), 3);
		assertTrue("testData2 is not square", !m2.isSquare());
	}

	/** test copy functions */
	public void testCopyFunctions() {
		Array2DRowRealMatrix m1 = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(m1.getData());
		assertEquals(m2, m1);
		Array2DRowRealMatrix m3 = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m4 = new Array2DRowRealMatrix(m3.getData(), false);
		assertEquals(m4, m3);
	}

	/** test add */
	public void testAdd() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix mInv = new Array2DRowRealMatrix(testDataInv);
		RealMatrix mPlusMInv = m.add(mInv);
		double[][] sumEntries = mPlusMInv.getData();
		for (int row = 0; row < m.getRowDimension(); row++) {
			for (int col = 0; col < m.getColumnDimension(); col++) {
				assertEquals("sum entry entry", testDataPlusInv[row][col], sumEntries[row][col], entryTolerance);
			}
		}
	}

	/** test add failure */
	public void testAddFail() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testData2);
		try {
			m.add(m2);
			fail("IllegalArgumentException expected");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	/** test norm */
	public void testNorm() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testData2);
		assertEquals("testData norm", 14d, m.getNorm(), entryTolerance);
		assertEquals("testData2 norm", 7d, m2.getNorm(), entryTolerance);
	}

	/** test Frobenius norm */
	public void testFrobeniusNorm() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testData2);
		assertEquals("testData Frobenius norm", Math.sqrt(117.0), m.getFrobeniusNorm(), entryTolerance);
		assertEquals("testData2 Frobenius norm", Math.sqrt(52.0), m2.getFrobeniusNorm(), entryTolerance);
	}

	/** test m-n = m + -n */
	public void testPlusMinus() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testDataInv);
		TestUtils.assertEquals("m-n = m + -n", m.subtract(m2), m2.scalarMultiply(-1d).add(m), entryTolerance);
		try {
			m.subtract(new Array2DRowRealMatrix(testData2));
			fail("Expecting illegalArgumentException");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	/** test multiply */
	public void testMultiply() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix mInv = new Array2DRowRealMatrix(testDataInv);
		Array2DRowRealMatrix identity = new Array2DRowRealMatrix(id);
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix(testData2);
		TestUtils.assertEquals("inverse multiply", m.multiply(mInv), identity, entryTolerance);
		TestUtils.assertEquals("inverse multiply", mInv.multiply(m), identity, entryTolerance);
		TestUtils.assertEquals("identity multiply", m.multiply(identity), m, entryTolerance);
		TestUtils.assertEquals("identity multiply", identity.multiply(mInv), mInv, entryTolerance);
		TestUtils.assertEquals("identity multiply", m2.multiply(identity), m2, entryTolerance);
		try {
			m.multiply(new Array2DRowRealMatrix(bigSingular));
			fail("Expecting illegalArgumentException");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	// Additional Test for Array2DRowRealMatrixTest.testMultiply

	private double[][] d3 = new double[][] { { 1, 2, 3, 4 }, { 5, 6, 7, 8 } };
	private double[][] d4 = new double[][] { { 1 }, { 2 }, { 3 }, { 4 } };
	private double[][] d5 = new double[][] { { 30 }, { 70 } };

	public void testMultiply2() {
		RealMatrix m3 = new Array2DRowRealMatrix(d3);
		RealMatrix m4 = new Array2DRowRealMatrix(d4);
		RealMatrix m5 = new Array2DRowRealMatrix(d5);
		TestUtils.assertEquals("m3*m4=m5", m3.multiply(m4), m5, entryTolerance);
	}

	/** test trace */
	public void testTrace() {
		RealMatrix m = new Array2DRowRealMatrix(id);
		assertEquals("identity trace", 3d, m.getTrace(), entryTolerance);
		m = new Array2DRowRealMatrix(testData2);
		try {
			m.getTrace();
			fail("Expecting NonSquareMatrixException");
		} catch (NonSquareMatrixException ex) {
			// ignored
		}
	}

	/** test sclarAdd */
	public void testScalarAdd() {
		RealMatrix m = new Array2DRowRealMatrix(testData);
		TestUtils.assertEquals("scalar add", new Array2DRowRealMatrix(testDataPlus2), m.scalarAdd(2d), entryTolerance);
	}

	/** test operate */
	public void testOperate() {
		RealMatrix m = new Array2DRowRealMatrix(id);
		TestUtils.assertEquals("identity operate", testVector, m.operate(testVector), entryTolerance);
		TestUtils.assertEquals("identity operate", testVector, m.operate(new ArrayRealVector(testVector)).getData(),
				entryTolerance);
		m = new Array2DRowRealMatrix(bigSingular);
		try {
			m.operate(testVector);
			fail("Expecting illegalArgumentException");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	/** test issue MATH-209 */
	public void testMath209() {
		RealMatrix a = new Array2DRowRealMatrix(new double[][] { { 1, 2 }, { 3, 4 }, { 5, 6 } }, false);
		double[] b = a.operate(new double[] { 1, 1 });
		assertEquals(a.getRowDimension(), b.length);
		assertEquals(3.0, b[0], 1.0e-12);
		assertEquals(7.0, b[1], 1.0e-12);
		assertEquals(11.0, b[2], 1.0e-12);
	}

	/** test transpose */
	public void testTranspose() {
		RealMatrix m = new Array2DRowRealMatrix(testData);
		RealMatrix mIT = new LUDecompositionImpl(m).getSolver().getInverse().transpose();
		RealMatrix mTI = new LUDecompositionImpl(m.transpose()).getSolver().getInverse();
		TestUtils.assertEquals("inverse-transpose", mIT, mTI, normTolerance);
		m = new Array2DRowRealMatrix(testData2);
		RealMatrix mt = new Array2DRowRealMatrix(testData2T);
		TestUtils.assertEquals("transpose", mt, m.transpose(), normTolerance);
	}

	/** test preMultiply by vector */
	public void testPremultiplyVector() {
		RealMatrix m = new Array2DRowRealMatrix(testData);
		TestUtils.assertEquals("premultiply", m.preMultiply(testVector), preMultTest, normTolerance);
		TestUtils.assertEquals("premultiply", m.preMultiply(new ArrayRealVector(testVector).getData()), preMultTest,
				normTolerance);
		m = new Array2DRowRealMatrix(bigSingular);
		try {
			m.preMultiply(testVector);
			fail("expecting IllegalArgumentException");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	public void testPremultiply() {
		RealMatrix m3 = new Array2DRowRealMatrix(d3);
		RealMatrix m4 = new Array2DRowRealMatrix(d4);
		RealMatrix m5 = new Array2DRowRealMatrix(d5);
		TestUtils.assertEquals("m3*m4=m5", m4.preMultiply(m3), m5, entryTolerance);

		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix mInv = new Array2DRowRealMatrix(testDataInv);
		Array2DRowRealMatrix identity = new Array2DRowRealMatrix(id);
		TestUtils.assertEquals("inverse multiply", m.preMultiply(mInv), identity, entryTolerance);
		TestUtils.assertEquals("inverse multiply", mInv.preMultiply(m), identity, entryTolerance);
		TestUtils.assertEquals("identity multiply", m.preMultiply(identity), m, entryTolerance);
		TestUtils.assertEquals("identity multiply", identity.preMultiply(mInv), mInv, entryTolerance);
		try {
			m.preMultiply(new Array2DRowRealMatrix(bigSingular));
			fail("Expecting illegalArgumentException");
		} catch (IllegalArgumentException ex) {
			// ignored
		}
	}

	public void testGetVectors() {
		RealMatrix m = new Array2DRowRealMatrix(testData);
		TestUtils.assertEquals("get row", m.getRow(0), testDataRow1, entryTolerance);
		TestUtils.assertEquals("get col", m.getColumn(2), testDataCol3, entryTolerance);
		try {
			m.getRow(10);
			fail("expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// ignored
		}
		try {
			m.getColumn(-1);
			fail("expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// ignored
		}
	}

	public void testGetEntry() {
		RealMatrix m = new Array2DRowRealMatrix(testData);
		assertEquals("get entry", m.getEntry(0, 1), 2d, entryTolerance);
		try {
			m.getEntry(10, 4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	/** test examples in user guide */
	public void testExamples() {
		// Create a real matrix with two rows and three columns
		double[][] matrixData = { { 1d, 2d, 3d }, { 2d, 5d, 3d } };
		RealMatrix m = new Array2DRowRealMatrix(matrixData);
		// One more with three rows, two columns
		double[][] matrixData2 = { { 1d, 2d }, { 2d, 5d }, { 1d, 7d } };
		RealMatrix n = new Array2DRowRealMatrix(matrixData2);
		// Now multiply m by n
		RealMatrix p = m.multiply(n);
		assertEquals(2, p.getRowDimension());
		assertEquals(2, p.getColumnDimension());
		// Invert p
		RealMatrix pInverse = new LUDecompositionImpl(p).getSolver().getInverse();
		assertEquals(2, pInverse.getRowDimension());
		assertEquals(2, pInverse.getColumnDimension());

		// Solve example
		double[][] coefficientsData = { { 2, 3, -2 }, { -1, 7, 6 }, { 4, -3, -5 } };
		RealMatrix coefficients = new Array2DRowRealMatrix(coefficientsData);
		double[] constants = { 1, -2, 1 };
		double[] solution = new LUDecompositionImpl(coefficients).getSolver().solve(constants);
		assertEquals(2 * solution[0] + 3 * solution[1] - 2 * solution[2], constants[0], 1E-12);
		assertEquals(-1 * solution[0] + 7 * solution[1] + 6 * solution[2], constants[1], 1E-12);
		assertEquals(4 * solution[0] - 3 * solution[1] - 5 * solution[2], constants[2], 1E-12);

	}

	// test submatrix accessors
	public void testGetSubMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		checkGetSubMatrix(m, subRows23Cols00, 2, 3, 0, 0, false);
		checkGetSubMatrix(m, subRows00Cols33, 0, 0, 3, 3, false);
		checkGetSubMatrix(m, subRows01Cols23, 0, 1, 2, 3, false);
		checkGetSubMatrix(m, subRows02Cols13, new int[] { 0, 2 }, new int[] { 1, 3 }, false);
		checkGetSubMatrix(m, subRows03Cols12, new int[] { 0, 3 }, new int[] { 1, 2 }, false);
		checkGetSubMatrix(m, subRows03Cols123, new int[] { 0, 3 }, new int[] { 1, 2, 3 }, false);
		checkGetSubMatrix(m, subRows20Cols123, new int[] { 2, 0 }, new int[] { 1, 2, 3 }, false);
		checkGetSubMatrix(m, subRows31Cols31, new int[] { 3, 1 }, new int[] { 3, 1 }, false);
		checkGetSubMatrix(m, subRows31Cols31, new int[] { 3, 1 }, new int[] { 3, 1 }, false);
		checkGetSubMatrix(m, null, 1, 0, 2, 4, true);
		checkGetSubMatrix(m, null, -1, 1, 2, 2, true);
		checkGetSubMatrix(m, null, 1, 0, 2, 2, true);
		checkGetSubMatrix(m, null, 1, 0, 2, 4, true);
		checkGetSubMatrix(m, null, new int[] {}, new int[] { 0 }, true);
		checkGetSubMatrix(m, null, new int[] { 0 }, new int[] { 4 }, true);
	}

	private void checkGetSubMatrix(RealMatrix m, double[][] reference, int startRow, int endRow, int startColumn,
			int endColumn, boolean mustFail) {
		try {
			RealMatrix sub = m.getSubMatrix(startRow, endRow, startColumn, endColumn);
			assertEquals(new Array2DRowRealMatrix(reference), sub);
			if (mustFail) {
				fail("Expecting MatrixIndexException");
			}
		} catch (MatrixIndexException e) {
			if (!mustFail) {
				throw e;
			}
		}
	}

	private void checkGetSubMatrix(RealMatrix m, double[][] reference, int[] selectedRows, int[] selectedColumns,
			boolean mustFail) {
		try {
			RealMatrix sub = m.getSubMatrix(selectedRows, selectedColumns);
			assertEquals(new Array2DRowRealMatrix(reference), sub);
			if (mustFail) {
				fail("Expecting MatrixIndexException");
			}
		} catch (MatrixIndexException e) {
			if (!mustFail) {
				throw e;
			}
		}
	}

	public void testCopySubMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		checkCopy(m, subRows23Cols00, 2, 3, 0, 0, false);
		checkCopy(m, subRows00Cols33, 0, 0, 3, 3, false);
		checkCopy(m, subRows01Cols23, 0, 1, 2, 3, false);
		checkCopy(m, subRows02Cols13, new int[] { 0, 2 }, new int[] { 1, 3 }, false);
		checkCopy(m, subRows03Cols12, new int[] { 0, 3 }, new int[] { 1, 2 }, false);
		checkCopy(m, subRows03Cols123, new int[] { 0, 3 }, new int[] { 1, 2, 3 }, false);
		checkCopy(m, subRows20Cols123, new int[] { 2, 0 }, new int[] { 1, 2, 3 }, false);
		checkCopy(m, subRows31Cols31, new int[] { 3, 1 }, new int[] { 3, 1 }, false);
		checkCopy(m, subRows31Cols31, new int[] { 3, 1 }, new int[] { 3, 1 }, false);

		checkCopy(m, null, 1, 0, 2, 4, true);
		checkCopy(m, null, -1, 1, 2, 2, true);
		checkCopy(m, null, 1, 0, 2, 2, true);
		checkCopy(m, null, 1, 0, 2, 4, true);
		checkCopy(m, null, new int[] {}, new int[] { 0 }, true);
		checkCopy(m, null, new int[] { 0 }, new int[] { 4 }, true);
	}

	private void checkCopy(RealMatrix m, double[][] reference, int startRow, int endRow, int startColumn, int endColumn,
			boolean mustFail) {
		try {
			double[][] sub = (reference == null) ? new double[1][1] : new double[reference.length][reference[0].length];
			m.copySubMatrix(startRow, endRow, startColumn, endColumn, sub);
			assertEquals(new Array2DRowRealMatrix(reference), new Array2DRowRealMatrix(sub));
			if (mustFail) {
				fail("Expecting MatrixIndexException");
			}
		} catch (MatrixIndexException e) {
			if (!mustFail) {
				throw e;
			}
		}
	}

	private void checkCopy(RealMatrix m, double[][] reference, int[] selectedRows, int[] selectedColumns,
			boolean mustFail) {
		try {
			double[][] sub = (reference == null) ? new double[1][1] : new double[reference.length][reference[0].length];
			m.copySubMatrix(selectedRows, selectedColumns, sub);
			assertEquals(new Array2DRowRealMatrix(reference), new Array2DRowRealMatrix(sub));
			if (mustFail) {
				fail("Expecting MatrixIndexException");
			}
		} catch (MatrixIndexException e) {
			if (!mustFail) {
				throw e;
			}
		}
	}

	public void testGetRowMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealMatrix mRow0 = new Array2DRowRealMatrix(subRow0);
		RealMatrix mRow3 = new Array2DRowRealMatrix(subRow3);
		assertEquals("Row0", mRow0, m.getRowMatrix(0));
		assertEquals("Row3", mRow3, m.getRowMatrix(3));
		try {
			m.getRowMatrix(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getRowMatrix(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetRowMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealMatrix mRow3 = new Array2DRowRealMatrix(subRow3);
		assertNotSame(mRow3, m.getRowMatrix(0));
		m.setRowMatrix(0, mRow3);
		assertEquals(mRow3, m.getRowMatrix(0));
		try {
			m.setRowMatrix(-1, mRow3);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setRowMatrix(0, m);
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	public void testGetColumnMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealMatrix mColumn1 = new Array2DRowRealMatrix(subColumn1);
		RealMatrix mColumn3 = new Array2DRowRealMatrix(subColumn3);
		assertEquals("Column1", mColumn1, m.getColumnMatrix(1));
		assertEquals("Column3", mColumn3, m.getColumnMatrix(3));
		try {
			m.getColumnMatrix(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getColumnMatrix(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetColumnMatrix() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealMatrix mColumn3 = new Array2DRowRealMatrix(subColumn3);
		assertNotSame(mColumn3, m.getColumnMatrix(1));
		m.setColumnMatrix(1, mColumn3);
		assertEquals(mColumn3, m.getColumnMatrix(1));
		try {
			m.setColumnMatrix(-1, mColumn3);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setColumnMatrix(0, m);
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	public void testGetRowVector() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealVector mRow0 = new ArrayRealVector(subRow0[0]);
		RealVector mRow3 = new ArrayRealVector(subRow3[0]);
		assertEquals("Row0", mRow0, m.getRowVector(0));
		assertEquals("Row3", mRow3, m.getRowVector(3));
		try {
			m.getRowVector(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getRowVector(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetRowVector() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealVector mRow3 = new ArrayRealVector(subRow3[0]);
		assertNotSame(mRow3, m.getRowMatrix(0));
		m.setRowVector(0, mRow3);
		assertEquals(mRow3, m.getRowVector(0));
		try {
			m.setRowVector(-1, mRow3);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setRowVector(0, new ArrayRealVector(5));
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	public void testGetColumnVector() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealVector mColumn1 = columnToVector(subColumn1);
		RealVector mColumn3 = columnToVector(subColumn3);
		assertEquals("Column1", mColumn1, m.getColumnVector(1));
		assertEquals("Column3", mColumn3, m.getColumnVector(3));
		try {
			m.getColumnVector(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getColumnVector(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetColumnVector() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		RealVector mColumn3 = columnToVector(subColumn3);
		assertNotSame(mColumn3, m.getColumnVector(1));
		m.setColumnVector(1, mColumn3);
		assertEquals(mColumn3, m.getColumnVector(1));
		try {
			m.setColumnVector(-1, mColumn3);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setColumnVector(0, new ArrayRealVector(5));
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	private RealVector columnToVector(double[][] column) {
		double[] data = new double[column.length];
		for (int i = 0; i < data.length; ++i) {
			data[i] = column[i][0];
		}
		return new ArrayRealVector(data, false);
	}

	public void testGetRow() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		checkArrays(subRow0[0], m.getRow(0));
		checkArrays(subRow3[0], m.getRow(3));
		try {
			m.getRow(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getRow(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetRow() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		assertTrue(subRow3[0][0] != m.getRow(0)[0]);
		m.setRow(0, subRow3[0]);
		checkArrays(subRow3[0], m.getRow(0));
		try {
			m.setRow(-1, subRow3[0]);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setRow(0, new double[5]);
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	public void testGetColumn() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		double[] mColumn1 = columnToArray(subColumn1);
		double[] mColumn3 = columnToArray(subColumn3);
		checkArrays(mColumn1, m.getColumn(1));
		checkArrays(mColumn3, m.getColumn(3));
		try {
			m.getColumn(-1);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getColumn(4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testSetColumn() {
		RealMatrix m = new Array2DRowRealMatrix(subTestData);
		double[] mColumn3 = columnToArray(subColumn3);
		assertTrue(mColumn3[0] != m.getColumn(1)[0]);
		m.setColumn(1, mColumn3);
		checkArrays(mColumn3, m.getColumn(1));
		try {
			m.setColumn(-1, mColumn3);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.setColumn(0, new double[5]);
			fail("Expecting InvalidMatrixException");
		} catch (InvalidMatrixException ex) {
			// expected
		}
	}

	private double[] columnToArray(double[][] column) {
		double[] data = new double[column.length];
		for (int i = 0; i < data.length; ++i) {
			data[i] = column[i][0];
		}
		return data;
	}

	private void checkArrays(double[] expected, double[] actual) {
		assertEquals(expected.length, actual.length);
		for (int i = 0; i < expected.length; ++i) {
			assertEquals(expected[i], actual[i]);
		}
	}

	public void testEqualsAndHashCode() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		Array2DRowRealMatrix m1 = (Array2DRowRealMatrix) m.copy();
		Array2DRowRealMatrix mt = (Array2DRowRealMatrix) m.transpose();
		assertTrue(m.hashCode() != mt.hashCode());
		assertEquals(m.hashCode(), m1.hashCode());
		assertEquals(m, m);
		assertEquals(m, m1);
		assertFalse(m.equals(null));
		assertFalse(m.equals(mt));
		assertFalse(m.equals(new Array2DRowRealMatrix(bigSingular)));
	}

	public void testToString() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		assertEquals("Array2DRowRealMatrix{{1.0,2.0,3.0},{2.0,5.0,3.0},{1.0,0.0,8.0}}", m.toString());
		m = new Array2DRowRealMatrix();
		assertEquals("Array2DRowRealMatrix{}", m.toString());
	}

	public void testSetSubMatrix() throws Exception {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		m.setSubMatrix(detData2, 1, 1);
		RealMatrix expected = MatrixUtils
				.createRealMatrix(new double[][] { { 1.0, 2.0, 3.0 }, { 2.0, 1.0, 3.0 }, { 1.0, 2.0, 4.0 } });
		assertEquals(expected, m);

		m.setSubMatrix(detData2, 0, 0);
		expected = MatrixUtils
				.createRealMatrix(new double[][] { { 1.0, 3.0, 3.0 }, { 2.0, 4.0, 3.0 }, { 1.0, 2.0, 4.0 } });
		assertEquals(expected, m);

		m.setSubMatrix(testDataPlus2, 0, 0);
		expected = MatrixUtils
				.createRealMatrix(new double[][] { { 3.0, 4.0, 5.0 }, { 4.0, 7.0, 5.0 }, { 3.0, 2.0, 10.0 } });
		assertEquals(expected, m);

		// dimension overflow
		try {
			m.setSubMatrix(testData, 1, 1);
			fail("expecting MatrixIndexException");
		} catch (MatrixIndexException e) {
			// expected
		}
		// dimension underflow
		try {
			m.setSubMatrix(testData, -1, 1);
			fail("expecting MatrixIndexException");
		} catch (MatrixIndexException e) {
			// expected
		}
		try {
			m.setSubMatrix(testData, 1, -1);
			fail("expecting MatrixIndexException");
		} catch (MatrixIndexException e) {
			// expected
		}

		// null
		try {
			m.setSubMatrix(null, 1, 1);
			fail("expecting NullPointerException");
		} catch (NullPointerException e) {
			// expected
		}
		Array2DRowRealMatrix m2 = new Array2DRowRealMatrix();
		try {
			m2.setSubMatrix(testData, 0, 1);
			fail("expecting IllegalStateException");
		} catch (IllegalStateException e) {
			// expected
		}
		try {
			m2.setSubMatrix(testData, 1, 0);
			fail("expecting IllegalStateException");
		} catch (IllegalStateException e) {
			// expected
		}

		// ragged
		try {
			m.setSubMatrix(new double[][] { { 1 }, { 2, 3 } }, 0, 0);
			fail("expecting IllegalArgumentException");
		} catch (IllegalArgumentException e) {
			// expected
		}

		// empty
		try {
			m.setSubMatrix(new double[][] { {} }, 0, 0);
			fail("expecting IllegalArgumentException");
		} catch (IllegalArgumentException e) {
			// expected
		}

	}

	public void testWalk() {
		int rows = 150;
		int columns = 75;

		RealMatrix m = new Array2DRowRealMatrix(rows, columns);
		m.walkInRowOrder(new SetVisitor());
		GetVisitor getVisitor = new GetVisitor();
		m.walkInOptimizedOrder(getVisitor);
		assertEquals(rows * columns, getVisitor.getCount());

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInRowOrder(new SetVisitor(), 1, rows - 2, 1, columns - 2);
		getVisitor = new GetVisitor();
		m.walkInOptimizedOrder(getVisitor, 1, rows - 2, 1, columns - 2);
		assertEquals((rows - 2) * (columns - 2), getVisitor.getCount());
		for (int i = 0; i < rows; ++i) {
			assertEquals(0.0, m.getEntry(i, 0), 0);
			assertEquals(0.0, m.getEntry(i, columns - 1), 0);
		}
		for (int j = 0; j < columns; ++j) {
			assertEquals(0.0, m.getEntry(0, j), 0);
			assertEquals(0.0, m.getEntry(rows - 1, j), 0);
		}

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInColumnOrder(new SetVisitor());
		getVisitor = new GetVisitor();
		m.walkInOptimizedOrder(getVisitor);
		assertEquals(rows * columns, getVisitor.getCount());

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInColumnOrder(new SetVisitor(), 1, rows - 2, 1, columns - 2);
		getVisitor = new GetVisitor();
		m.walkInOptimizedOrder(getVisitor, 1, rows - 2, 1, columns - 2);
		assertEquals((rows - 2) * (columns - 2), getVisitor.getCount());
		for (int i = 0; i < rows; ++i) {
			assertEquals(0.0, m.getEntry(i, 0), 0);
			assertEquals(0.0, m.getEntry(i, columns - 1), 0);
		}
		for (int j = 0; j < columns; ++j) {
			assertEquals(0.0, m.getEntry(0, j), 0);
			assertEquals(0.0, m.getEntry(rows - 1, j), 0);
		}

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInOptimizedOrder(new SetVisitor());
		getVisitor = new GetVisitor();
		m.walkInRowOrder(getVisitor);
		assertEquals(rows * columns, getVisitor.getCount());

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInOptimizedOrder(new SetVisitor(), 1, rows - 2, 1, columns - 2);
		getVisitor = new GetVisitor();
		m.walkInRowOrder(getVisitor, 1, rows - 2, 1, columns - 2);
		assertEquals((rows - 2) * (columns - 2), getVisitor.getCount());
		for (int i = 0; i < rows; ++i) {
			assertEquals(0.0, m.getEntry(i, 0), 0);
			assertEquals(0.0, m.getEntry(i, columns - 1), 0);
		}
		for (int j = 0; j < columns; ++j) {
			assertEquals(0.0, m.getEntry(0, j), 0);
			assertEquals(0.0, m.getEntry(rows - 1, j), 0);
		}

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInOptimizedOrder(new SetVisitor());
		getVisitor = new GetVisitor();
		m.walkInColumnOrder(getVisitor);
		assertEquals(rows * columns, getVisitor.getCount());

		m = new Array2DRowRealMatrix(rows, columns);
		m.walkInOptimizedOrder(new SetVisitor(), 1, rows - 2, 1, columns - 2);
		getVisitor = new GetVisitor();
		m.walkInColumnOrder(getVisitor, 1, rows - 2, 1, columns - 2);
		assertEquals((rows - 2) * (columns - 2), getVisitor.getCount());
		for (int i = 0; i < rows; ++i) {
			assertEquals(0.0, m.getEntry(i, 0), 0);
			assertEquals(0.0, m.getEntry(i, columns - 1), 0);
		}
		for (int j = 0; j < columns; ++j) {
			assertEquals(0.0, m.getEntry(0, j), 0);
			assertEquals(0.0, m.getEntry(rows - 1, j), 0);
		}

	}

	public void testSerial() {
		Array2DRowRealMatrix m = new Array2DRowRealMatrix(testData);
		assertEquals(m, TestUtils.serializeAndRecover(m));
	}

	private static class SetVisitor extends DefaultRealMatrixChangingVisitor {
		@Override
		public double visit(int i, int j, double value) {
			return i + j / 1024.0;
		}
	}

	private static class GetVisitor extends DefaultRealMatrixPreservingVisitor {
		private int count = 0;

		@Override
		public void visit(int i, int j, double value) {
			++count;
			assertEquals(i + j / 1024.0, value, 0.0);
		}

		public int getCount() {
			return count;
		}
	}

	// --------------- -----------------Protected methods

	/** extracts the l and u matrices from compact lu representation */
	protected void splitLU(RealMatrix lu, double[][] lowerData, double[][] upperData) throws InvalidMatrixException {
		if (!lu.isSquare() || lowerData.length != lowerData[0].length || upperData.length != upperData[0].length
				|| lowerData.length != upperData.length || lowerData.length != lu.getRowDimension()) {
			throw new InvalidMatrixException("incorrect dimensions");
		}
		int n = lu.getRowDimension();
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < n; j++) {
				if (j < i) {
					lowerData[i][j] = lu.getEntry(i, j);
					upperData[i][j] = 0d;
				} else if (i == j) {
					lowerData[i][j] = 1d;
					upperData[i][j] = lu.getEntry(i, j);
				} else {
					lowerData[i][j] = 0d;
					upperData[i][j] = lu.getEntry(i, j);
				}
			}
		}
	}

	/**
	 * Returns the result of applying the given row permutation to the matrix
	 */
	protected RealMatrix permuteRows(RealMatrix matrix, int[] permutation) {
		if (!matrix.isSquare() || matrix.getRowDimension() != permutation.length) {
			throw new IllegalArgumentException("dimension mismatch");
		}
		int n = matrix.getRowDimension();
		int m = matrix.getColumnDimension();
		double out[][] = new double[m][n];
		for (int i = 0; i < n; i++) {
			for (int j = 0; j < m; j++) {
				out[i][j] = matrix.getEntry(permutation[i], j);
			}
		}
		return new Array2DRowRealMatrix(out);
	}

	// /** Useful for debugging */
	// private void dumpMatrix(RealMatrix m) {
	// for (int i = 0; i < m.getRowDimension(); i++) {
	// String os = "";
	// for (int j = 0; j < m.getColumnDimension(); j++) {
	// os += m.getEntry(i, j) + " ";
	// }
	// System.out.println(os);
	// }
	// }

}
