de.isabeldrostfromm.sof.util.VectorsTest.java Source code

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Here is the source code for de.isabeldrostfromm.sof.util.VectorsTest.java

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/**
 * Copyright (C) 2013 Isabel Drost-Fromm
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of 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 de.isabeldrostfromm.sof.util;

import org.apache.mahout.math.SequentialAccessSparseVector;
import org.apache.mahout.math.Vector;
import org.junit.Test;

import com.carrotsearch.randomizedtesting.RandomizedTest;
import com.carrotsearch.randomizedtesting.annotations.Repeat;

public class VectorsTest extends RandomizedTest {

    @Test
    @Repeat(iterations = 5)
    public void testAppendOne() {
        SequentialAccessSparseVector vec = randomVector();
        Vector result = Vectors.append(vec);
        assertEquals("Appending a single vector should result that same vector.", vec, result);
    }

    @Test
    @Repeat(iterations = 10)
    public void testAppendTwo() {
        Vector vecA = randomVector();
        Vector vecB = randomVector();
        Vector result = Vectors.append(vecA, vecB);
        double sum = Math.pow(vecA.norm(2), 2) + Math.pow(vecB.norm(2), 2);
        double length = Math.sqrt(sum);
        assertEquals("Appending two vectors should result in a vector of added length.", length, result.norm(2),
                0.00001);
    }

    @Test
    @Repeat(iterations = 10)
    public void testCreation() {
        Vector vec = randomVector();
        double[] entries = new double[vec.getNumNondefaultElements()];
        int index = 0;
        for (Vector.Element e : vec) {
            entries[index] = e.get();
            index++;
        }
        Vector result = Vectors.newSequentialAccessSparseVector(entries);
        assertEquals("Original vector should have same length as the one created from its entries.", vec.norm(2),
                result.norm(2), 0.0001);
    }

    private SequentialAccessSparseVector randomVector() {
        int length = atMost(100);
        SequentialAccessSparseVector vec = new SequentialAccessSparseVector(length);
        for (int i = 0; i < length; i++) {
            vec.setQuick(i, randomDouble());
        }
        return vec;
    }
}