Commons Math example source code file (ArrayFieldVectorTest.java)

This example Commons Math source code file (ArrayFieldVectorTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Math tags/keywords

arrayfieldvector, arrayfieldvector, exception, fieldmatrix, fieldvector, fieldvector, fieldvectortestimpl, fraction, fraction, illegalargumentexception, illegalargumentexception, io, matrixindexexception, reflection, t, unsupportedoperationexception

The Commons Math ArrayFieldVectorTest.java source code

/*
 * 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 java.io.Serializable;
import java.lang.reflect.Array;

import junit.framework.TestCase;

import org.apache.commons.math.Field;
import org.apache.commons.math.FieldElement;
import org.apache.commons.math.TestUtils;
import org.apache.commons.math.fraction.Fraction;
import org.apache.commons.math.fraction.FractionField;

/**
 * Test cases for the {@link ArrayFieldVector} class.
 *
 * @version $Revision: 903044 $ $Date: 2010-01-25 21:00:09 -0500 (Mon, 25 Jan 2010) $
 */
public class ArrayFieldVectorTest extends TestCase {

    //
    protected Fraction[][] ma1 = {
            {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)}
    };
    protected Fraction[] vec1 = {new Fraction(1), new Fraction(2), new Fraction(3)};
    protected Fraction[] vec2 = {new Fraction(4), new Fraction(5), new Fraction(6)};
    protected Fraction[] vec3 = {new Fraction(7), new Fraction(8), new Fraction(9)};
    protected Fraction[] vec4 = { 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)};
    protected Fraction[] vec_null = {new Fraction(0), new Fraction(0), new Fraction(0)};
    protected Fraction[] dvec1 = {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)};
    protected Fraction[][] mat1 = {
            {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)}
    };

    // Testclass to test the FieldVector<Fraction> interface
    // only with enough content to support the test
    public static class FieldVectorTestImpl<T extends FieldElement
        implements FieldVector<T>, Serializable {

        private static final long serialVersionUID = 3970959016014158539L;

        private final Field<T> field;

        /** Entries of the vector. */
        protected T[] data;

        /** Build an array of elements.
         * @param length size of the array to build
         * @return a new array
         */
        @SuppressWarnings("unchecked") // field is of type T
        private T[] buildArray(final int length) {
            return (T[]) Array.newInstance(field.getZero().getClass(), length);
        }

        public FieldVectorTestImpl(T[] d) {
            field = d[0].getField();
            data = d.clone();
        }

        public Field<T> getField() {
            return field;
        }

        private UnsupportedOperationException unsupported() {
            return new UnsupportedOperationException("Not supported, unneeded for test purposes");
        }

        public FieldVector<T> copy() {
            throw unsupported();
        }

        public FieldVector<T> add(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> add(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> subtract(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> subtract(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> mapAdd(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapAddToSelf(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapSubtract(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapSubtractToSelf(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapMultiply(T d) {
            T[] out = buildArray(data.length);
            for (int i = 0; i < data.length; i++) {
                out[i] = data[i].multiply(d);
            }
            return new FieldVectorTestImpl<T>(out);
        }

        public FieldVector<T> mapMultiplyToSelf(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapDivide(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapDivideToSelf(T d) {
            throw unsupported();
        }

        public FieldVector<T> mapInv() {
            throw unsupported();
        }

        public FieldVector<T> mapInvToSelf() {
            throw unsupported();
        }

        public FieldVector<T> ebeMultiply(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> ebeMultiply(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> ebeDivide(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> ebeDivide(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public T[] getData() {
            return data.clone();
        }

        public T dotProduct(FieldVector<T> v) throws IllegalArgumentException {
            T dot = field.getZero();
            for (int i = 0; i < data.length; i++) {
                dot = dot.add(data[i].multiply(v.getEntry(i)));
            }
            return dot;
        }

        public T dotProduct(T[] v) throws IllegalArgumentException {
            T dot = field.getZero();
            for (int i = 0; i < data.length; i++) {
                dot = dot.add(data[i].multiply(v[i]));
            }
            return dot;
        }

        public FieldVector<T> projection(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldVector<T> projection(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldMatrix<T> outerProduct(FieldVector v) throws IllegalArgumentException {
            throw unsupported();
        }

        public FieldMatrix<T> outerProduct(T[] v) throws IllegalArgumentException {
            throw unsupported();
        }

        public T getEntry(int index) throws MatrixIndexException {
            return data[index];
        }

        public int getDimension() {
            return data.length;
        }

        public FieldVector<T> append(FieldVector v) {
            throw unsupported();
        }

        public FieldVector<T> append(T d) {
            throw unsupported();
        }

        public FieldVector<T> append(T[] a) {
            throw unsupported();
        }

        public FieldVector<T> getSubVector(int index, int n) throws MatrixIndexException {
            throw unsupported();
        }

        public void setEntry(int index, T value) throws MatrixIndexException {
            throw unsupported();
        }

        public void setSubVector(int index, FieldVector<T> v) throws MatrixIndexException {
            throw unsupported();
        }

        public void setSubVector(int index, T[] v) throws MatrixIndexException {
            throw unsupported();
        }

        public void set(T value) {
            throw unsupported();
        }

        public T[] toArray() {
            throw unsupported();
        }

    }

    public void testConstructors() {

        ArrayFieldVector<Fraction> v0 = new ArrayFieldVector(FractionField.getInstance());
        assertEquals(0, v0.getDimension());

        ArrayFieldVector<Fraction> v1 = new ArrayFieldVector(FractionField.getInstance(), 7);
        assertEquals(7, v1.getDimension());
        assertEquals(new Fraction(0), v1.getEntry(6));

        ArrayFieldVector<Fraction> v2 = new ArrayFieldVector(5, new Fraction(123, 100));
        assertEquals(5, v2.getDimension());
        assertEquals(new Fraction(123, 100), v2.getEntry(4));

        ArrayFieldVector<Fraction> v3 = new ArrayFieldVector(vec1);
        assertEquals(3, v3.getDimension());
        assertEquals(new Fraction(2), v3.getEntry(1));

        ArrayFieldVector<Fraction> v4 = new ArrayFieldVector(vec4, 3, 2);
        assertEquals(2, v4.getDimension());
        assertEquals(new Fraction(4), v4.getEntry(0));
        try {
            new ArrayFieldVector<Fraction>(vec4, 8, 3);
            fail("IllegalArgumentException expected");
        } catch (IllegalArgumentException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        FieldVector<Fraction> v5_i = new ArrayFieldVector(dvec1);
        assertEquals(9, v5_i.getDimension());
        assertEquals(new Fraction(9), v5_i.getEntry(8));

        ArrayFieldVector<Fraction> v5 = new ArrayFieldVector(dvec1);
        assertEquals(9, v5.getDimension());
        assertEquals(new Fraction(9), v5.getEntry(8));

        ArrayFieldVector<Fraction> v6 = new ArrayFieldVector(dvec1, 3, 2);
        assertEquals(2, v6.getDimension());
        assertEquals(new Fraction(4), v6.getEntry(0));
        try {
            new ArrayFieldVector<Fraction>(dvec1, 8, 3);
            fail("IllegalArgumentException expected");
        } catch (IllegalArgumentException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        ArrayFieldVector<Fraction> v7 = new ArrayFieldVector(v1);
        assertEquals(7, v7.getDimension());
        assertEquals(new Fraction(0), v7.getEntry(6));

        FieldVectorTestImpl<Fraction> v7_i = new FieldVectorTestImpl(vec1);

        ArrayFieldVector<Fraction> v7_2 = new ArrayFieldVector(v7_i);
        assertEquals(3, v7_2.getDimension());
        assertEquals(new Fraction(2), v7_2.getEntry(1));

        ArrayFieldVector<Fraction> v8 = new ArrayFieldVector(v1, true);
        assertEquals(7, v8.getDimension());
        assertEquals(new Fraction(0), v8.getEntry(6));
        assertNotSame("testData not same object ", v1.data, v8.data);

        ArrayFieldVector<Fraction> v8_2 = new ArrayFieldVector(v1, false);
        assertEquals(7, v8_2.getDimension());
        assertEquals(new Fraction(0), v8_2.getEntry(6));
        assertEquals(v1.data, v8_2.data);

        ArrayFieldVector<Fraction> v9 = new ArrayFieldVector(v1, v3);
        assertEquals(10, v9.getDimension());
        assertEquals(new Fraction(1), v9.getEntry(7));

    }

    public void testDataInOut() {

        ArrayFieldVector<Fraction> v1 = new ArrayFieldVector(vec1);
        ArrayFieldVector<Fraction> v2 = new ArrayFieldVector(vec2);
        ArrayFieldVector<Fraction> v4 = new ArrayFieldVector(vec4);
        FieldVectorTestImpl<Fraction> v2_t = new FieldVectorTestImpl(vec2);

        FieldVector<Fraction> v_append_1 = v1.append(v2);
        assertEquals(6, v_append_1.getDimension());
        assertEquals(new Fraction(4), v_append_1.getEntry(3));

        FieldVector<Fraction> v_append_2 = v1.append(new Fraction(2));
        assertEquals(4, v_append_2.getDimension());
        assertEquals(new Fraction(2), v_append_2.getEntry(3));

        FieldVector<Fraction> v_append_3 = v1.append(vec2);
        assertEquals(6, v_append_3.getDimension());
        assertEquals(new Fraction(4), v_append_3.getEntry(3));

        FieldVector<Fraction> v_append_4 = v1.append(v2_t);
        assertEquals(6, v_append_4.getDimension());
        assertEquals(new Fraction(4), v_append_4.getEntry(3));

        FieldVector<Fraction> v_copy = v1.copy();
        assertEquals(3, v_copy.getDimension());
        assertNotSame("testData not same object ", v1.data, v_copy.getData());

        Fraction[] a_frac = v1.toArray();
        assertEquals(3, a_frac.length);
        assertNotSame("testData not same object ", v1.data, a_frac);


//      ArrayFieldVector<Fraction> vout4 = (ArrayFieldVector) v1.clone();
//      assertEquals(3, vout4.getDimension());
//      assertEquals(v1.data, vout4.data);


        FieldVector<Fraction> vout5 = v4.getSubVector(3, 3);
        assertEquals(3, vout5.getDimension());
        assertEquals(new Fraction(5), vout5.getEntry(1));
        try {
            v4.getSubVector(3, 7);
            fail("MatrixIndexException expected");
        } catch (MatrixIndexException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        ArrayFieldVector<Fraction> v_set1 = (ArrayFieldVector) v1.copy();
        v_set1.setEntry(1, new Fraction(11));
        assertEquals(new Fraction(11), v_set1.getEntry(1));
        try {
            v_set1.setEntry(3, new Fraction(11));
            fail("MatrixIndexException expected");
        } catch (MatrixIndexException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        ArrayFieldVector<Fraction> v_set2 = (ArrayFieldVector) v4.copy();
        v_set2.set(3, v1);
        assertEquals(new Fraction(1), v_set2.getEntry(3));
        assertEquals(new Fraction(7), v_set2.getEntry(6));
        try {
            v_set2.set(7, v1);
            fail("MatrixIndexException expected");
        } catch (MatrixIndexException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        ArrayFieldVector<Fraction> v_set3 = (ArrayFieldVector) v1.copy();
        v_set3.set(new Fraction(13));
        assertEquals(new Fraction(13), v_set3.getEntry(2));

        try {
            v_set3.getEntry(23);
            fail("ArrayIndexOutOfBoundsException expected");
        } catch (ArrayIndexOutOfBoundsException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        ArrayFieldVector<Fraction> v_set4 = (ArrayFieldVector) v4.copy();
        v_set4.setSubVector(3, v2_t);
        assertEquals(new Fraction(4), v_set4.getEntry(3));
        assertEquals(new Fraction(7), v_set4.getEntry(6));
        try {
            v_set4.setSubVector(7, v2_t);
            fail("MatrixIndexException expected");
        } catch (MatrixIndexException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }


        ArrayFieldVector<Fraction> vout10 = (ArrayFieldVector) v1.copy();
        ArrayFieldVector<Fraction> vout10_2 = (ArrayFieldVector) v1.copy();
        assertEquals(vout10, vout10_2);
        vout10_2.setEntry(0, new Fraction(11, 10));
        assertNotSame(vout10, vout10_2);

    }

    public void testMapFunctions() {
        ArrayFieldVector<Fraction> v1 = new ArrayFieldVector(vec1);

        //octave =  v1 .+ 2.0
        FieldVector<Fraction> v_mapAdd = v1.mapAdd(new Fraction(2));
        Fraction[] result_mapAdd = {new Fraction(3), new Fraction(4), new Fraction(5)};
        checkArray("compare vectors" ,result_mapAdd,v_mapAdd.getData());

        //octave =  v1 .+ 2.0
        FieldVector<Fraction> v_mapAddToSelf = v1.copy();
        v_mapAddToSelf.mapAddToSelf(new Fraction(2));
        Fraction[] result_mapAddToSelf = {new Fraction(3), new Fraction(4), new Fraction(5)};
        checkArray("compare vectors" ,result_mapAddToSelf,v_mapAddToSelf.getData());

        //octave =  v1 .- 2.0
        FieldVector<Fraction> v_mapSubtract = v1.mapSubtract(new Fraction(2));
        Fraction[] result_mapSubtract = {new Fraction(-1), new Fraction(0), new Fraction(1)};
        checkArray("compare vectors" ,result_mapSubtract,v_mapSubtract.getData());

        //octave =  v1 .- 2.0
        FieldVector<Fraction> v_mapSubtractToSelf = v1.copy();
        v_mapSubtractToSelf.mapSubtractToSelf(new Fraction(2));
        Fraction[] result_mapSubtractToSelf = {new Fraction(-1), new Fraction(0), new Fraction(1)};
        checkArray("compare vectors" ,result_mapSubtractToSelf,v_mapSubtractToSelf.getData());

        //octave =  v1 .* 2.0
        FieldVector<Fraction> v_mapMultiply = v1.mapMultiply(new Fraction(2));
        Fraction[] result_mapMultiply = {new Fraction(2), new Fraction(4), new Fraction(6)};
        checkArray("compare vectors" ,result_mapMultiply,v_mapMultiply.getData());

        //octave =  v1 .* 2.0
        FieldVector<Fraction> v_mapMultiplyToSelf = v1.copy();
        v_mapMultiplyToSelf.mapMultiplyToSelf(new Fraction(2));
        Fraction[] result_mapMultiplyToSelf = {new Fraction(2), new Fraction(4), new Fraction(6)};
        checkArray("compare vectors" ,result_mapMultiplyToSelf,v_mapMultiplyToSelf.getData());

        //octave =  v1 ./ 2.0
        FieldVector<Fraction> v_mapDivide = v1.mapDivide(new Fraction(2));
        Fraction[] result_mapDivide = {new Fraction(1, 2), new Fraction(1), new Fraction(3, 2)};
        checkArray("compare vectors" ,result_mapDivide,v_mapDivide.getData());

        //octave =  v1 ./ 2.0
        FieldVector<Fraction> v_mapDivideToSelf = v1.copy();
        v_mapDivideToSelf.mapDivideToSelf(new Fraction(2));
        Fraction[] result_mapDivideToSelf = {new Fraction(1, 2), new Fraction(1), new Fraction(3, 2)};
        checkArray("compare vectors" ,result_mapDivideToSelf,v_mapDivideToSelf.getData());

        //octave =  v1 .^-1
        FieldVector<Fraction> v_mapInv = v1.mapInv();
        Fraction[] result_mapInv = {new Fraction(1),new Fraction(1, 2),new Fraction(1, 3)};
        checkArray("compare vectors" ,result_mapInv,v_mapInv.getData());

        //octave =  v1 .^-1
        FieldVector<Fraction> v_mapInvToSelf = v1.copy();
        v_mapInvToSelf.mapInvToSelf();
        Fraction[] result_mapInvToSelf = {new Fraction(1),new Fraction(1, 2),new Fraction(1, 3)};
        checkArray("compare vectors" ,result_mapInvToSelf,v_mapInvToSelf.getData());

    }

    public void testBasicFunctions() {
        ArrayFieldVector<Fraction> v1 = new ArrayFieldVector(vec1);
        ArrayFieldVector<Fraction> v2 = new ArrayFieldVector(vec2);
        new ArrayFieldVector<Fraction>(vec_null);

        FieldVectorTestImpl<Fraction> v2_t = new FieldVectorTestImpl(vec2);

        //octave =  v1 + v2
        ArrayFieldVector<Fraction> v_add = v1.add(v2);
        Fraction[] result_add = {new Fraction(5), new Fraction(7), new Fraction(9)};
        checkArray("compare vect" ,v_add.getData(),result_add);

        FieldVectorTestImpl<Fraction> vt2 = new FieldVectorTestImpl(vec2);
        FieldVector<Fraction> v_add_i = v1.add(vt2);
        Fraction[] result_add_i = {new Fraction(5), new Fraction(7), new Fraction(9)};
        checkArray("compare vect" ,v_add_i.getData(),result_add_i);

        //octave =  v1 - v2
        ArrayFieldVector<Fraction> v_subtract = v1.subtract(v2);
        Fraction[] result_subtract = {new Fraction(-3), new Fraction(-3), new Fraction(-3)};
        checkArray("compare vect" ,v_subtract.getData(),result_subtract);

        FieldVector<Fraction> v_subtract_i = v1.subtract(vt2);
        Fraction[] result_subtract_i = {new Fraction(-3), new Fraction(-3), new Fraction(-3)};
        checkArray("compare vect" ,v_subtract_i.getData(),result_subtract_i);

        // octave v1 .* v2
        ArrayFieldVector<Fraction>  v_ebeMultiply = v1.ebeMultiply(v2);
        Fraction[] result_ebeMultiply = {new Fraction(4), new Fraction(10), new Fraction(18)};
        checkArray("compare vect" ,v_ebeMultiply.getData(),result_ebeMultiply);

        FieldVector<Fraction>  v_ebeMultiply_2 = v1.ebeMultiply(v2_t);
        Fraction[] result_ebeMultiply_2 = {new Fraction(4), new Fraction(10), new Fraction(18)};
        checkArray("compare vect" ,v_ebeMultiply_2.getData(),result_ebeMultiply_2);

        // octave v1 ./ v2
        ArrayFieldVector<Fraction>  v_ebeDivide = v1.ebeDivide(v2);
        Fraction[] result_ebeDivide = {new Fraction(1, 4), new Fraction(2, 5), new Fraction(1, 2)};
        checkArray("compare vect" ,v_ebeDivide.getData(),result_ebeDivide);

        FieldVector<Fraction>  v_ebeDivide_2 = v1.ebeDivide(v2_t);
        Fraction[] result_ebeDivide_2 = {new Fraction(1, 4), new Fraction(2, 5), new Fraction(1, 2)};
        checkArray("compare vect" ,v_ebeDivide_2.getData(),result_ebeDivide_2);

        // octave  dot(v1,v2)
        Fraction dot =  v1.dotProduct(v2);
        assertEquals("compare val ",new Fraction(32), dot);

        // octave  dot(v1,v2_t)
        Fraction dot_2 =  v1.dotProduct(v2_t);
        assertEquals("compare val ",new Fraction(32), dot_2);

        FieldMatrix<Fraction> m_outerProduct = v1.outerProduct(v2);
        assertEquals("compare val ",new Fraction(4), m_outerProduct.getEntry(0,0));

        FieldMatrix<Fraction> m_outerProduct_2 = v1.outerProduct(v2_t);
        assertEquals("compare val ",new Fraction(4), m_outerProduct_2.getEntry(0,0));

        ArrayFieldVector<Fraction> v_projection = v1.projection(v2);
        Fraction[] result_projection = {new Fraction(128, 77), new Fraction(160, 77), new Fraction(192, 77)};
        checkArray("compare vect", v_projection.getData(), result_projection);

        FieldVector<Fraction> v_projection_2 = v1.projection(v2_t);
        Fraction[] result_projection_2 = {new Fraction(128, 77), new Fraction(160, 77), new Fraction(192, 77)};
        checkArray("compare vect", v_projection_2.getData(), result_projection_2);

    }

    public void testMisc() {
        ArrayFieldVector<Fraction> v1 = new ArrayFieldVector(vec1);
        ArrayFieldVector<Fraction> v4 = new ArrayFieldVector(vec4);
        FieldVector<Fraction> v4_2 = new ArrayFieldVector(vec4);

        String out1 = v1.toString();
        assertTrue("some output ",  out1.length()!=0);
        /*
         Fraction[] dout1 = v1.copyOut();
        assertEquals(3, dout1.length);
        assertNotSame("testData not same object ", v1.data, dout1);
         */
        try {
            v1.checkVectorDimensions(2);
            fail("IllegalArgumentException expected");
        } catch (IllegalArgumentException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

       try {
            v1.checkVectorDimensions(v4);
            fail("IllegalArgumentException expected");
        } catch (IllegalArgumentException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

        try {
            v1.checkVectorDimensions(v4_2);
            fail("IllegalArgumentException expected");
        } catch (IllegalArgumentException ex) {
            // expected behavior
        } catch (Exception e) {
            fail("wrong exception caught");
        }

    }

    public void testSerial()  {
        ArrayFieldVector<Fraction> v = new ArrayFieldVector(vec1);
        assertEquals(v,TestUtils.serializeAndRecover(v));
    }

    /** verifies that two vectors are equals */
    protected void checkArray(String msg, Fraction[] m, Fraction[] n) {
        if (m.length != n.length) {
            fail("vectors have different lengths");
        }
        for (int i = 0; i < m.length; i++) {
            assertEquals(msg + " " +  i + " elements differ", m[i],n[i]);
        }
    }

}