/*
 * 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 OpenMapRealMatrix} class.
 * 
 * @version $Revision$ $Date: 2008-11-07 06:48:13 -0800 (Fri, 07 Nov 2008) $
 */
public final class SparseRealMatrixTest 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 SparseRealMatrixTest(String name) {
		super(name);
	}

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

	/** test dimensions */
	public void testDimensions() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		OpenMapRealMatrix m2 = createSparseMatrix(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() {
		OpenMapRealMatrix m1 = createSparseMatrix(testData);
		RealMatrix m2 = m1.copy();
		assertEquals(m1.getClass(), m2.getClass());
		assertEquals((m2), m1);
		OpenMapRealMatrix m3 = createSparseMatrix(testData);
		RealMatrix m4 = m3.copy();
		assertEquals(m3.getClass(), m4.getClass());
		assertEquals((m4), m3);
	}

	/** test add */
	public void testAdd() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		OpenMapRealMatrix mInv = createSparseMatrix(testDataInv);
		OpenMapRealMatrix mDataPlusInv = createSparseMatrix(testDataPlusInv);
		RealMatrix mPlusMInv = m.add(mInv);
		for (int row = 0; row < m.getRowDimension(); row++) {
			for (int col = 0; col < m.getColumnDimension(); col++) {
				assertEquals("sum entry entry", mDataPlusInv.getEntry(row, col), mPlusMInv.getEntry(row, col),
						entryTolerance);
			}
		}
	}

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

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

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

	/** test multiply */
	public void testMultiply() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		OpenMapRealMatrix mInv = createSparseMatrix(testDataInv);
		OpenMapRealMatrix identity = createSparseMatrix(id);
		OpenMapRealMatrix m2 = createSparseMatrix(testData2);
		assertClose("inverse multiply", m.multiply(mInv), identity, entryTolerance);
		assertClose("inverse multiply", m.multiply(new BlockRealMatrix(testDataInv)), identity, entryTolerance);
		assertClose("inverse multiply", mInv.multiply(m), identity, entryTolerance);
		assertClose("identity multiply", m.multiply(identity), m, entryTolerance);
		assertClose("identity multiply", identity.multiply(mInv), mInv, entryTolerance);
		assertClose("identity multiply", m2.multiply(identity), m2, entryTolerance);
		try {
			m.multiply(createSparseMatrix(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 = createSparseMatrix(d3);
		RealMatrix m4 = createSparseMatrix(d4);
		RealMatrix m5 = createSparseMatrix(d5);
		assertClose("m3*m4=m5", m3.multiply(m4), m5, entryTolerance);
	}

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

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

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

	/** test issue MATH-209 */
	public void testMath209() {
		RealMatrix a = createSparseMatrix(new double[][] { { 1, 2 }, { 3, 4 }, { 5, 6 } });
		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 = createSparseMatrix(testData);
		RealMatrix mIT = new LUDecompositionImpl(m).getSolver().getInverse().transpose();
		RealMatrix mTI = new LUDecompositionImpl(m.transpose()).getSolver().getInverse();
		assertClose("inverse-transpose", mIT, mTI, normTolerance);
		m = createSparseMatrix(testData2);
		RealMatrix mt = createSparseMatrix(testData2T);
		assertClose("transpose", mt, m.transpose(), normTolerance);
	}

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

	public void testPremultiply() {
		RealMatrix m3 = createSparseMatrix(d3);
		RealMatrix m4 = createSparseMatrix(d4);
		RealMatrix m5 = createSparseMatrix(d5);
		assertClose("m3*m4=m5", m4.preMultiply(m3), m5, entryTolerance);

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

	public void testGetVectors() {
		RealMatrix m = createSparseMatrix(testData);
		assertClose("get row", m.getRow(0), testDataRow1, entryTolerance);
		assertClose("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 = createSparseMatrix(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 = createSparseMatrix(matrixData);
		// One more with three rows, two columns
		double[][] matrixData2 = { { 1d, 2d }, { 2d, 5d }, { 1d, 7d } };
		RealMatrix n = createSparseMatrix(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 = createSparseMatrix(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 testSubMatrix() {
		RealMatrix m = createSparseMatrix(subTestData);
		RealMatrix mRows23Cols00 = createSparseMatrix(subRows23Cols00);
		RealMatrix mRows00Cols33 = createSparseMatrix(subRows00Cols33);
		RealMatrix mRows01Cols23 = createSparseMatrix(subRows01Cols23);
		RealMatrix mRows02Cols13 = createSparseMatrix(subRows02Cols13);
		RealMatrix mRows03Cols12 = createSparseMatrix(subRows03Cols12);
		RealMatrix mRows03Cols123 = createSparseMatrix(subRows03Cols123);
		RealMatrix mRows20Cols123 = createSparseMatrix(subRows20Cols123);
		RealMatrix mRows31Cols31 = createSparseMatrix(subRows31Cols31);
		assertEquals("Rows23Cols00", mRows23Cols00, m.getSubMatrix(2, 3, 0, 0));
		assertEquals("Rows00Cols33", mRows00Cols33, m.getSubMatrix(0, 0, 3, 3));
		assertEquals("Rows01Cols23", mRows01Cols23, m.getSubMatrix(0, 1, 2, 3));
		assertEquals("Rows02Cols13", mRows02Cols13, m.getSubMatrix(new int[] { 0, 2 }, new int[] { 1, 3 }));
		assertEquals("Rows03Cols12", mRows03Cols12, m.getSubMatrix(new int[] { 0, 3 }, new int[] { 1, 2 }));
		assertEquals("Rows03Cols123", mRows03Cols123, m.getSubMatrix(new int[] { 0, 3 }, new int[] { 1, 2, 3 }));
		assertEquals("Rows20Cols123", mRows20Cols123, m.getSubMatrix(new int[] { 2, 0 }, new int[] { 1, 2, 3 }));
		assertEquals("Rows31Cols31", mRows31Cols31, m.getSubMatrix(new int[] { 3, 1 }, new int[] { 3, 1 }));
		assertEquals("Rows31Cols31", mRows31Cols31, m.getSubMatrix(new int[] { 3, 1 }, new int[] { 3, 1 }));

		try {
			m.getSubMatrix(1, 0, 2, 4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getSubMatrix(-1, 1, 2, 2);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getSubMatrix(1, 0, 2, 2);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getSubMatrix(1, 0, 2, 4);
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getSubMatrix(new int[] {}, new int[] { 0 });
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
		try {
			m.getSubMatrix(new int[] { 0 }, new int[] { 4 });
			fail("Expecting MatrixIndexException");
		} catch (MatrixIndexException ex) {
			// expected
		}
	}

	public void testGetRowMatrix() {
		RealMatrix m = createSparseMatrix(subTestData);
		RealMatrix mRow0 = createSparseMatrix(subRow0);
		RealMatrix mRow3 = createSparseMatrix(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 testGetColumnMatrix() {
		RealMatrix m = createSparseMatrix(subTestData);
		RealMatrix mColumn1 = createSparseMatrix(subColumn1);
		RealMatrix mColumn3 = createSparseMatrix(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 testGetRowVector() {
		RealMatrix m = createSparseMatrix(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 testGetColumnVector() {
		RealMatrix m = createSparseMatrix(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
		}
	}

	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 testEqualsAndHashCode() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		OpenMapRealMatrix m1 = (OpenMapRealMatrix) m.copy();
		OpenMapRealMatrix mt = (OpenMapRealMatrix) 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(createSparseMatrix(bigSingular)));
	}

	public void testToString() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		assertEquals("OpenMapRealMatrix{{1.0,2.0,3.0},{2.0,5.0,3.0},{1.0,0.0,8.0}}", m.toString());
		m = new OpenMapRealMatrix(1, 1);
		assertEquals("OpenMapRealMatrix{{0.0}}", m.toString());
	}

	public void testSetSubMatrix() throws Exception {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		m.setSubMatrix(detData2, 1, 1);
		RealMatrix expected = createSparseMatrix(
				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 = createSparseMatrix(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 = createSparseMatrix(new double[][] { { 3.0, 4.0, 5.0 }, { 4.0, 7.0, 5.0 }, { 3.0, 2.0, 10.0 } });
		assertEquals(expected, m);

		// javadoc example
		OpenMapRealMatrix matrix = createSparseMatrix(
				new double[][] { { 1, 2, 3, 4 }, { 5, 6, 7, 8 }, { 9, 0, 1, 2 } });
		matrix.setSubMatrix(new double[][] { { 3, 4 }, { 5, 6 } }, 1, 1);
		expected = createSparseMatrix(new double[][] { { 1, 2, 3, 4 }, { 5, 3, 4, 8 }, { 9, 5, 6, 2 } });
		assertEquals(expected, matrix);

		// 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
		}
		try {
			new OpenMapRealMatrix(0, 0);
			fail("expecting IllegalArgumentException");
		} catch (IllegalArgumentException 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 testSerial() {
		OpenMapRealMatrix m = createSparseMatrix(testData);
		assertEquals(m, TestUtils.serializeAndRecover(m));
	}

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

	/** verifies that two matrices are close (1-norm) */
	protected void assertClose(String msg, RealMatrix m, RealMatrix n, double tolerance) {
		assertTrue(msg, m.subtract(n).getNorm() < tolerance);
	}

	/** verifies that two vectors are close (sup norm) */
	protected void assertClose(String msg, double[] m, double[] n, double tolerance) {
		if (m.length != n.length) {
			fail("vectors not same length");
		}
		for (int i = 0; i < m.length; i++) {
			assertEquals(msg + " " + i + " elements differ", m[i], n[i], tolerance);
		}
	}

	private OpenMapRealMatrix createSparseMatrix(double[][] data) {
		OpenMapRealMatrix matrix = new OpenMapRealMatrix(data.length, data[0].length);
		for (int row = 0; row < data.length; row++) {
			for (int col = 0; col < data[row].length; col++) {
				matrix.setEntry(row, col, data[row][col]);
			}
		}
		return matrix;
	}

}
