/*
 * 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 org.apache.commons.math.Field;
import org.apache.commons.math.fraction.Fraction;
import org.apache.commons.math.fraction.FractionConversionException;
import org.apache.commons.math.fraction.FractionField;

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

/**
 * Test cases for the {@link SparseFieldMatrix} class.
 *
 * @version $Revision: 728186 $ $Date: 2009-04-20 11:42:11 -0700 (Mon, 20 Apr
 *          2009) $
 */
public class SparseFieldMatrixTest extends TestCase {
	// 3 x 3 identity matrix
	protected Fraction[][] id = { { new Fraction(1), new Fraction(0), new Fraction(0) },
			{ new Fraction(0), new Fraction(1), new Fraction(0) },
			{ new Fraction(0), new Fraction(0), new Fraction(1) } };
	// Test data for group operations
	protected Fraction[][] testData = { { new Fraction(1), new Fraction(2), new Fraction(3) },
			{ new Fraction(2), new Fraction(5), new Fraction(3) },
			{ new Fraction(1), new Fraction(0), new Fraction(8) } };
	protected Fraction[][] testDataLU = null;
	protected Fraction[][] testDataPlus2 = { { new Fraction(3), new Fraction(4), new Fraction(5) },
			{ new Fraction(4), new Fraction(7), new Fraction(5) },
			{ new Fraction(3), new Fraction(2), new Fraction(10) } };
	protected Fraction[][] testDataMinus = { { new Fraction(-1), new Fraction(-2), new Fraction(-3) },
			{ new Fraction(-2), new Fraction(-5), new Fraction(-3) },
			{ new Fraction(-1), new Fraction(0), new Fraction(-8) } };
	protected Fraction[] testDataRow1 = { new Fraction(1), new Fraction(2), new Fraction(3) };
	protected Fraction[] testDataCol3 = { new Fraction(3), new Fraction(3), new Fraction(8) };
	protected Fraction[][] testDataInv = { { new Fraction(-40), new Fraction(16), new Fraction(9) },
			{ new Fraction(13), new Fraction(-5), new Fraction(-3) },
			{ new Fraction(5), new Fraction(-2), new Fraction(-1) } };
	protected Fraction[] preMultTest = { new Fraction(8), new Fraction(12), new Fraction(33) };
	protected Fraction[][] testData2 = { { new Fraction(1), new Fraction(2), new Fraction(3) },
			{ new Fraction(2), new Fraction(5), new Fraction(3) } };
	protected Fraction[][] testData2T = { { new Fraction(1), new Fraction(2) }, { new Fraction(2), new Fraction(5) },
			{ new Fraction(3), new Fraction(3) } };
	protected Fraction[][] testDataPlusInv = { { new Fraction(-39), new Fraction(18), new Fraction(12) },
			{ new Fraction(15), new Fraction(0), new Fraction(0) },
			{ new Fraction(6), new Fraction(-2), new Fraction(7) } };

	// lu decomposition tests
	protected Fraction[][] luData = { { new Fraction(2), new Fraction(3), new Fraction(3) },
			{ new Fraction(0), new Fraction(5), new Fraction(7) },
			{ new Fraction(6), new Fraction(9), new Fraction(8) } };
	protected Fraction[][] luDataLUDecomposition = null;

	// singular matrices
	protected Fraction[][] singular = { { new Fraction(2), new Fraction(3) }, { new Fraction(2), new Fraction(3) } };
	protected Fraction[][] bigSingular = { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) },
			{ new Fraction(2), new Fraction(5), new Fraction(3), new Fraction(4) },
			{ new Fraction(7), new Fraction(3), new Fraction(256), new Fraction(1930) },
			{ new Fraction(3), new Fraction(7), new Fraction(6), new Fraction(8) } }; // 4th

	// row
	// =
	// 1st
	// +
	// 2nd
	protected Fraction[][] detData = { { new Fraction(1), new Fraction(2), new Fraction(3) },
			{ new Fraction(4), new Fraction(5), new Fraction(6) },
			{ new Fraction(7), new Fraction(8), new Fraction(10) } };
	protected Fraction[][] detData2 = { { new Fraction(1), new Fraction(3) }, { new Fraction(2), new Fraction(4) } };

	// vectors
	protected Fraction[] testVector = { new Fraction(1), new Fraction(2), new Fraction(3) };
	protected Fraction[] testVector2 = { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) };

	// submatrix accessor tests
	protected Fraction[][] subTestData = null;

	// array selections
	protected Fraction[][] subRows02Cols13 = { { new Fraction(2), new Fraction(4) },
			{ new Fraction(4), new Fraction(8) } };
	protected Fraction[][] subRows03Cols12 = { { new Fraction(2), new Fraction(3) },
			{ new Fraction(5), new Fraction(6) } };
	protected Fraction[][] subRows03Cols123 = { { new Fraction(2), new Fraction(3), new Fraction(4) },
			{ new Fraction(5), new Fraction(6), new Fraction(7) } };

	// effective permutations
	protected Fraction[][] subRows20Cols123 = { { new Fraction(4), new Fraction(6), new Fraction(8) },
			{ new Fraction(2), new Fraction(3), new Fraction(4) } };
	protected Fraction[][] subRows31Cols31 = null;

	// contiguous ranges
	protected Fraction[][] subRows01Cols23 = null;
	protected Fraction[][] subRows23Cols00 = { { new Fraction(2) }, { new Fraction(4) } };
	protected Fraction[][] subRows00Cols33 = { { new Fraction(4) } };

	// row matrices
	protected Fraction[][] subRow0 = { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) } };
	protected Fraction[][] subRow3 = { { new Fraction(4), new Fraction(5), new Fraction(6), new Fraction(7) } };

	// column matrices
	protected Fraction[][] subColumn1 = null;
	protected Fraction[][] subColumn3 = null;

	// tolerances
	protected double entryTolerance = 10E-16;
	protected double normTolerance = 10E-14;
	protected Field<Fraction> field = FractionField.getInstance();

	public SparseFieldMatrixTest(String name) {
		super(name);
		setupFractionArrays();
	}

	private void setupFractionArrays() {
		try {
			testDataLU = new Fraction[][] { { new Fraction(2), new Fraction(5), new Fraction(3) },
					{ new Fraction(.5d), new Fraction(-2.5d), new Fraction(6.5d) },
					{ new Fraction(0.5d), new Fraction(0.2d), new Fraction(.2d) } };
			luDataLUDecomposition = new Fraction[][] { { new Fraction(6), new Fraction(9), new Fraction(8) },
					{ new Fraction(0), new Fraction(5), new Fraction(7) },
					{ new Fraction(0.33333333333333), new Fraction(0), new Fraction(0.33333333333333) } };
			subTestData = new Fraction[][] { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) },
					{ new Fraction(1.5), new Fraction(2.5), new Fraction(3.5), new Fraction(4.5) },
					{ new Fraction(2), new Fraction(4), new Fraction(6), new Fraction(8) },
					{ new Fraction(4), new Fraction(5), new Fraction(6), new Fraction(7) } };
			subRows31Cols31 = new Fraction[][] { { new Fraction(7), new Fraction(5) },
					{ new Fraction(4.5), new Fraction(2.5) } };
			subRows01Cols23 = new Fraction[][] { { new Fraction(3), new Fraction(4) },
					{ new Fraction(3.5), new Fraction(4.5) } };
			subColumn1 = new Fraction[][] { { new Fraction(2) }, { new Fraction(2.5) }, { new Fraction(4) },
					{ new Fraction(5) } };
			subColumn3 = new Fraction[][] { { new Fraction(4) }, { new Fraction(4.5) }, { new Fraction(8) },
					{ new Fraction(7) } };
		} catch (FractionConversionException e) {
			// ignore, can't happen
		}

	}

	public static Test suite() {
		TestSuite suite = new TestSuite(SparseFieldMatrixTest.class);
		suite.setName("SparseFieldMatrix<Fraction> Tests");
		return suite;
	}

	/** test dimensions */
	public void testDimensions() {
		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		SparseFieldMatrix<Fraction> 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() {
		SparseFieldMatrix<Fraction> m1 = createSparseMatrix(testData);
		FieldMatrix<Fraction> m2 = m1.copy();
		assertEquals(m1.getClass(), m2.getClass());
		assertEquals((m2), m1);
		SparseFieldMatrix<Fraction> m3 = createSparseMatrix(testData);
		FieldMatrix<Fraction> m4 = m3.copy();
		assertEquals(m3.getClass(), m4.getClass());
		assertEquals((m4), m3);
	}

	/** test add */
	public void testAdd() {
		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		SparseFieldMatrix<Fraction> mInv = createSparseMatrix(testDataInv);
		SparseFieldMatrix<Fraction> mDataPlusInv = createSparseMatrix(testDataPlusInv);
		FieldMatrix<Fraction> 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).doubleValue(),
						mPlusMInv.getEntry(row, col).doubleValue(), entryTolerance);
			}
		}
	}

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

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

	/** test multiply */
	public void testMultiply() {
		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		SparseFieldMatrix<Fraction> mInv = createSparseMatrix(testDataInv);
		SparseFieldMatrix<Fraction> identity = createSparseMatrix(id);
		SparseFieldMatrix<Fraction> m2 = createSparseMatrix(testData2);
		assertClose("inverse multiply", m.multiply(mInv), identity, entryTolerance);
		assertClose("inverse multiply", m.multiply(new Array2DRowFieldMatrix<Fraction>(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 Fraction[][] d3 = new Fraction[][] { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) },
			{ new Fraction(5), new Fraction(6), new Fraction(7), new Fraction(8) } };
	private Fraction[][] d4 = new Fraction[][] { { new Fraction(1) }, { new Fraction(2) }, { new Fraction(3) },
			{ new Fraction(4) } };
	private Fraction[][] d5 = new Fraction[][] { { new Fraction(30) }, { new Fraction(70) } };

	public void testMultiply2() {
		FieldMatrix<Fraction> m3 = createSparseMatrix(d3);
		FieldMatrix<Fraction> m4 = createSparseMatrix(d4);
		FieldMatrix<Fraction> m5 = createSparseMatrix(d5);
		assertClose("m3*m4=m5", m3.multiply(m4), m5, entryTolerance);
	}

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

	/** test sclarAdd */
	public void testScalarAdd() {
		FieldMatrix<Fraction> m = createSparseMatrix(testData);
		assertClose("scalar add", createSparseMatrix(testDataPlus2), m.scalarAdd(new Fraction(2)), entryTolerance);
	}

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

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

	/** test transpose */
	public void testTranspose() {

		FieldMatrix<Fraction> m = createSparseMatrix(testData);
		FieldMatrix<Fraction> mIT = new FieldLUDecompositionImpl<Fraction>(m).getSolver().getInverse().transpose();
		FieldMatrix<Fraction> mTI = new FieldLUDecompositionImpl<Fraction>(m.transpose()).getSolver().getInverse();
		assertClose("inverse-transpose", mIT, mTI, normTolerance);
		m = createSparseMatrix(testData2);
		FieldMatrix<Fraction> mt = createSparseMatrix(testData2T);
		assertClose("transpose", mt, m.transpose(), normTolerance);
	}

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

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

		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		SparseFieldMatrix<Fraction> mInv = createSparseMatrix(testDataInv);
		SparseFieldMatrix<Fraction> 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() {
		FieldMatrix<Fraction> 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() {
		FieldMatrix<Fraction> m = createSparseMatrix(testData);
		assertEquals("get entry", m.getEntry(0, 1).doubleValue(), 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
		Fraction[][] matrixData = { { new Fraction(1), new Fraction(2), new Fraction(3) },
				{ new Fraction(2), new Fraction(5), new Fraction(3) } };
		FieldMatrix<Fraction> m = createSparseMatrix(matrixData);
		// One more with three rows, two columns
		Fraction[][] matrixData2 = { { new Fraction(1), new Fraction(2) }, { new Fraction(2), new Fraction(5) },
				{ new Fraction(1), new Fraction(7) } };
		FieldMatrix<Fraction> n = createSparseMatrix(matrixData2);
		// Now multiply m by n
		FieldMatrix<Fraction> p = m.multiply(n);
		assertEquals(2, p.getRowDimension());
		assertEquals(2, p.getColumnDimension());
		// Invert p
		FieldMatrix<Fraction> pInverse = new FieldLUDecompositionImpl<Fraction>(p).getSolver().getInverse();
		assertEquals(2, pInverse.getRowDimension());
		assertEquals(2, pInverse.getColumnDimension());

		// Solve example
		Fraction[][] coefficientsData = { { new Fraction(2), new Fraction(3), new Fraction(-2) },
				{ new Fraction(-1), new Fraction(7), new Fraction(6) },
				{ new Fraction(4), new Fraction(-3), new Fraction(-5) } };
		FieldMatrix<Fraction> coefficients = createSparseMatrix(coefficientsData);
		Fraction[] constants = { new Fraction(1), new Fraction(-2), new Fraction(1) };
		Fraction[] solution = new FieldLUDecompositionImpl<Fraction>(coefficients).getSolver().solve(constants);
		assertEquals(
				(new Fraction(2).multiply((solution[0])).add(new Fraction(3).multiply(solution[1]))
						.subtract(new Fraction(2).multiply(solution[2]))).doubleValue(),
				constants[0].doubleValue(), 1E-12);
		assertEquals(((new Fraction(-1).multiply(solution[0])).add(new Fraction(7).multiply(solution[1]))
				.add(new Fraction(6).multiply(solution[2]))).doubleValue(), constants[1].doubleValue(), 1E-12);
		assertEquals(
				((new Fraction(4).multiply(solution[0])).subtract(new Fraction(3).multiply(solution[1]))
						.subtract(new Fraction(5).multiply(solution[2]))).doubleValue(),
				constants[2].doubleValue(), 1E-12);

	}

	// test submatrix accessors
	public void testSubMatrix() {
		FieldMatrix<Fraction> m = createSparseMatrix(subTestData);
		FieldMatrix<Fraction> mRows23Cols00 = createSparseMatrix(subRows23Cols00);
		FieldMatrix<Fraction> mRows00Cols33 = createSparseMatrix(subRows00Cols33);
		FieldMatrix<Fraction> mRows01Cols23 = createSparseMatrix(subRows01Cols23);
		FieldMatrix<Fraction> mRows02Cols13 = createSparseMatrix(subRows02Cols13);
		FieldMatrix<Fraction> mRows03Cols12 = createSparseMatrix(subRows03Cols12);
		FieldMatrix<Fraction> mRows03Cols123 = createSparseMatrix(subRows03Cols123);
		FieldMatrix<Fraction> mRows20Cols123 = createSparseMatrix(subRows20Cols123);
		FieldMatrix<Fraction> 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() {
		FieldMatrix<Fraction> m = createSparseMatrix(subTestData);
		FieldMatrix<Fraction> mRow0 = createSparseMatrix(subRow0);
		FieldMatrix<Fraction> 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() {
		FieldMatrix<Fraction> m = createSparseMatrix(subTestData);
		FieldMatrix<Fraction> mColumn1 = createSparseMatrix(subColumn1);
		FieldMatrix<Fraction> 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() {
		FieldMatrix<Fraction> m = createSparseMatrix(subTestData);
		FieldVector<Fraction> mRow0 = new ArrayFieldVector<Fraction>(subRow0[0]);
		FieldVector<Fraction> mRow3 = new ArrayFieldVector<Fraction>(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() {
		FieldMatrix<Fraction> m = createSparseMatrix(subTestData);
		FieldVector<Fraction> mColumn1 = columnToVector(subColumn1);
		FieldVector<Fraction> 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 FieldVector<Fraction> columnToVector(Fraction[][] column) {
		Fraction[] data = new Fraction[column.length];
		for (int i = 0; i < data.length; ++i) {
			data[i] = column[i][0];
		}
		return new ArrayFieldVector<Fraction>(data, false);
	}

	public void testEqualsAndHashCode() {
		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		SparseFieldMatrix<Fraction> m1 = (SparseFieldMatrix<Fraction>) m.copy();
		SparseFieldMatrix<Fraction> mt = (SparseFieldMatrix<Fraction>) 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)));
	}

	/*
	 * Disable for now public void testToString() { SparseFieldMatrix<Fraction>
	 * m = createSparseMatrix(testData); assertEquals(
	 * "SparseFieldMatrix<Fraction>{{1.0,2.0,3.0},{2.0,5.0,3.0},{1.0,0.0,8.0}}",
	 * m.toString()); m = new SparseFieldMatrix<Fraction>(field, 1, 1);
	 * assertEquals("SparseFieldMatrix<Fraction>{{0.0}}", m.toString()); }
	 */

	public void testSetSubMatrix() throws Exception {
		SparseFieldMatrix<Fraction> m = createSparseMatrix(testData);
		m.setSubMatrix(detData2, 1, 1);
		FieldMatrix<Fraction> expected = createSparseMatrix(
				new Fraction[][] { { new Fraction(1), new Fraction(2), new Fraction(3) },
						{ new Fraction(2), new Fraction(1), new Fraction(3) },
						{ new Fraction(1), new Fraction(2), new Fraction(4) } });
		assertEquals(expected, m);

		m.setSubMatrix(detData2, 0, 0);
		expected = createSparseMatrix(new Fraction[][] { { new Fraction(1), new Fraction(3), new Fraction(3) },
				{ new Fraction(2), new Fraction(4), new Fraction(3) },
				{ new Fraction(1), new Fraction(2), new Fraction(4) } });
		assertEquals(expected, m);

		m.setSubMatrix(testDataPlus2, 0, 0);
		expected = createSparseMatrix(new Fraction[][] { { new Fraction(3), new Fraction(4), new Fraction(5) },
				{ new Fraction(4), new Fraction(7), new Fraction(5) },
				{ new Fraction(3), new Fraction(2), new Fraction(10) } });
		assertEquals(expected, m);

		// javadoc example
		SparseFieldMatrix<Fraction> matrix = createSparseMatrix(
				new Fraction[][] { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) },
						{ new Fraction(5), new Fraction(6), new Fraction(7), new Fraction(8) },
						{ new Fraction(9), new Fraction(0), new Fraction(1), new Fraction(2) } });
		matrix.setSubMatrix(
				new Fraction[][] { { new Fraction(3), new Fraction(4) }, { new Fraction(5), new Fraction(6) } }, 1, 1);
		expected = createSparseMatrix(
				new Fraction[][] { { new Fraction(1), new Fraction(2), new Fraction(3), new Fraction(4) },
						{ new Fraction(5), new Fraction(3), new Fraction(4), new Fraction(8) },
						{ new Fraction(9), new Fraction(5), new Fraction(6), new Fraction(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 SparseFieldMatrix<Fraction>(field, 0, 0);
			fail("expecting IllegalArgumentException");
		} catch (IllegalArgumentException e) {
			// expected
		}

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

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

	}

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

	/** verifies that two matrices are close (1-norm) */
	protected void assertClose(String msg, FieldMatrix<Fraction> m, FieldMatrix<Fraction> n, double tolerance) {
		for (int i = 0; i < m.getRowDimension(); i++) {
			for (int j = 0; j < m.getColumnDimension(); j++) {
				assertEquals(msg, m.getEntry(i, j).doubleValue(), n.getEntry(i, j).doubleValue(), tolerance);
			}

		}
	}

	/** verifies that two vectors are close (sup norm) */
	protected void assertClose(String msg, Fraction[] m, Fraction[] 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].doubleValue(), n[i].doubleValue(), tolerance);
		}
	}

	private SparseFieldMatrix<Fraction> createSparseMatrix(Fraction[][] data) {
		SparseFieldMatrix<Fraction> matrix = new SparseFieldMatrix<Fraction>(field, 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;
	}

}
