src/test/java/org/apache/commons/math3/stat/FrequencyTest.java

/*
 * 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.math3.stat;

import java.io.BufferedReader;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;


import org.apache.commons.math3.TestUtils;
import org.apache.commons.math3.exception.MathIllegalArgumentException;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;

/**
 * Test cases for the {@link Frequency} class.
 *
 */
public final class FrequencyTest {
    private static final long ONE_LONG = 1L;
    private static final long TWO_LONG = 2L;
    private static final long THREE_LONG = 3L;
    private static final int ONE = 1;
    private static final int TWO = 2;
    private static final int THREE = 3 ;
    private static final double TOLERANCE = 10E-15d;
    private static final char CHAR_A = 'a';

    private Frequency f = null;

    @Before
    public void setUp() {
        f = new Frequency();
    }

    /** test freq counts */
    @Test
    public void testCounts() {
        Assert.assertEquals("total count",0,f.getSumFreq());
        f.addValue(ONE_LONG);
        f.addValue(TWO_LONG);
        f.addValue(1);
        f.addValue(ONE);
        Assert.assertEquals("one frequency count",3,f.getCount(1));
        Assert.assertEquals("two frequency count",1,f.getCount(2));
        Assert.assertEquals("three frequency count",0,f.getCount(3));
        Assert.assertEquals("total count",4,f.getSumFreq());
        Assert.assertEquals("zero cumulative frequency", 0, f.getCumFreq(0));
        Assert.assertEquals("one cumulative frequency", 3,  f.getCumFreq(1));
        Assert.assertEquals("two cumulative frequency", 4,  f.getCumFreq(2));
        Assert.assertEquals("Integer argument cum freq",4, f.getCumFreq(Integer.valueOf(2)));
        Assert.assertEquals("five cumulative frequency", 4,  f.getCumFreq(5));
        Assert.assertEquals("foo cumulative frequency", 0,  f.getCumFreq("foo"));

        f.clear();
        Assert.assertEquals("total count",0,f.getSumFreq());

        // userguide examples -------------------------------------------------------------------
        f.addValue("one");
        f.addValue("One");
        f.addValue("oNe");
        f.addValue("Z");
        Assert.assertEquals("one cumulative frequency", 1 ,  f.getCount("one"));
        Assert.assertEquals("Z cumulative pct", 0.5,  f.getCumPct("Z"), TOLERANCE);
        Assert.assertEquals("z cumulative pct", 1.0,  f.getCumPct("z"), TOLERANCE);
        Assert.assertEquals("Ot cumulative pct", 0.25,  f.getCumPct("Ot"), TOLERANCE);
        f.clear();

        f = null;
        Frequency f = new Frequency();
        f.addValue(1);
        f.addValue(Integer.valueOf(1));
        f.addValue(Long.valueOf(1));
        f.addValue(2);
        f.addValue(Integer.valueOf(-1));
        Assert.assertEquals("1 count", 3, f.getCount(1));
        Assert.assertEquals("1 count", 3, f.getCount(Integer.valueOf(1)));
        Assert.assertEquals("0 cum pct", 0.2, f.getCumPct(0), TOLERANCE);
        Assert.assertEquals("1 pct", 0.6, f.getPct(Integer.valueOf(1)), TOLERANCE);
        Assert.assertEquals("-2 cum pct", 0, f.getCumPct(-2), TOLERANCE);
        Assert.assertEquals("10 cum pct", 1, f.getCumPct(10), TOLERANCE);

        f = null;
        f = new Frequency(String.CASE_INSENSITIVE_ORDER);
        f.addValue("one");
        f.addValue("One");
        f.addValue("oNe");
        f.addValue("Z");
        Assert.assertEquals("one count", 3 ,  f.getCount("one"));
        Assert.assertEquals("Z cumulative pct -- case insensitive", 1 ,  f.getCumPct("Z"), TOLERANCE);
        Assert.assertEquals("z cumulative pct -- case insensitive", 1 ,  f.getCumPct("z"), TOLERANCE);

        f = null;
        f = new Frequency();
        Assert.assertEquals(0L, f.getCount('a'));
        Assert.assertEquals(0L, f.getCumFreq('b'));
        TestUtils.assertEquals(Double.NaN, f.getPct('a'), 0.0);
        TestUtils.assertEquals(Double.NaN, f.getCumPct('b'), 0.0);
        f.addValue('a');
        f.addValue('b');
        f.addValue('c');
        f.addValue('d');
        Assert.assertEquals(1L, f.getCount('a'));
        Assert.assertEquals(2L, f.getCumFreq('b'));
        Assert.assertEquals(0.25, f.getPct('a'), 0.0);
        Assert.assertEquals(0.5, f.getCumPct('b'), 0.0);
        Assert.assertEquals(1.0, f.getCumPct('e'), 0.0);
    }

    /** test pcts */
    @Test
    public void testPcts() {
        f.addValue(ONE_LONG);
        f.addValue(TWO_LONG);
        f.addValue(ONE);
        f.addValue(TWO);
        f.addValue(THREE_LONG);
        f.addValue(THREE_LONG);
        f.addValue(3);
        f.addValue(THREE);
        Assert.assertEquals("one pct",0.25,f.getPct(1),TOLERANCE);
        Assert.assertEquals("two pct",0.25,f.getPct(Long.valueOf(2)),TOLERANCE);
        Assert.assertEquals("three pct",0.5,f.getPct(THREE_LONG),TOLERANCE);
        Assert.assertEquals("five pct",0,f.getPct(5),TOLERANCE);
        Assert.assertEquals("foo pct",0,f.getPct("foo"),TOLERANCE);
        Assert.assertEquals("one cum pct",0.25,f.getCumPct(1),TOLERANCE);
        Assert.assertEquals("two cum pct",0.50,f.getCumPct(Long.valueOf(2)),TOLERANCE);
        Assert.assertEquals("Integer argument",0.50,f.getCumPct(Integer.valueOf(2)),TOLERANCE);
        Assert.assertEquals("three cum pct",1.0,f.getCumPct(THREE_LONG),TOLERANCE);
        Assert.assertEquals("five cum pct",1.0,f.getCumPct(5),TOLERANCE);
        Assert.assertEquals("zero cum pct",0.0,f.getCumPct(0),TOLERANCE);
        Assert.assertEquals("foo cum pct",0,f.getCumPct("foo"),TOLERANCE);
    }

    /** test adding incomparable values */
    @Test
    public void testAdd() {
        char aChar = 'a';
        char bChar = 'b';
        String aString = "a";
        f.addValue(aChar);
        f.addValue(bChar);
        try {
            f.addValue(aString);
            Assert.fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        try {
            f.addValue(2);
            Assert.fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
        Assert.assertEquals("a pct",0.5,f.getPct(aChar),TOLERANCE);
        Assert.assertEquals("b cum pct",1.0,f.getCumPct(bChar),TOLERANCE);
        Assert.assertEquals("a string pct",0.0,f.getPct(aString),TOLERANCE);
        Assert.assertEquals("a string cum pct",0.0,f.getCumPct(aString),TOLERANCE);

        f = new Frequency();
        f.addValue("One");
        try {
            f.addValue(new Integer("One"));
            Assert.fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }
    }

    /** test empty table */
    @Test
    public void testEmptyTable() {
        Assert.assertEquals("freq sum, empty table", 0, f.getSumFreq());
        Assert.assertEquals("count, empty table", 0, f.getCount(0));
        Assert.assertEquals("count, empty table",0, f.getCount(Integer.valueOf(0)));
        Assert.assertEquals("cum freq, empty table", 0, f.getCumFreq(0));
        Assert.assertEquals("cum freq, empty table", 0, f.getCumFreq("x"));
        Assert.assertTrue("pct, empty table", Double.isNaN(f.getPct(0)));
        Assert.assertTrue("pct, empty table", Double.isNaN(f.getPct(Integer.valueOf(0))));
        Assert.assertTrue("cum pct, empty table", Double.isNaN(f.getCumPct(0)));
        Assert.assertTrue("cum pct, empty table", Double.isNaN(f.getCumPct(Integer.valueOf(0))));
    }

    @Test
    public void testNonComparableCumPct() {
        f.addValue("a");
        Assert.assertEquals("cum freq, single entry", 1.0d, f.getCumPct("a"),TOLERANCE);
        Assert.assertEquals("cum freq, single entry non comparable", 0.0d, f.getCumPct(100),TOLERANCE);
    }

    @Test
    public void testNonComparablePct() {
        f.addValue("a");
        Assert.assertEquals("cum freq, single entry", 1.0d, f.getPct("a"),TOLERANCE);
        Assert.assertEquals("cum freq, single entry non comparable", 0.0d, f.getPct(100),TOLERANCE);
    }

    /**
     * Tests toString()
     */
    @Test
    public void testToString() throws Exception {
        f.addValue(ONE_LONG);
        f.addValue(TWO_LONG);
        f.addValue(ONE);
        f.addValue(TWO);

        String s = f.toString();
        //System.out.println(s);
        Assert.assertNotNull(s);
        BufferedReader reader = new BufferedReader(new StringReader(s));
        String line = reader.readLine(); // header line
        Assert.assertNotNull(line);

        line = reader.readLine(); // one's or two's line
        Assert.assertNotNull(line);

        line = reader.readLine(); // one's or two's line
        Assert.assertNotNull(line);

        line = reader.readLine(); // no more elements
        Assert.assertNull(line);
    }

    @Test
    public void testIntegerValues() {
        Comparable<?> obj1 = null;
        obj1 = Integer.valueOf(1);
        Integer int1 = Integer.valueOf(1);
        f.addValue(obj1);
        f.addValue(int1);
        f.addValue(2);
        f.addValue(Long.valueOf(2));
        Assert.assertEquals("Integer 1 count", 2, f.getCount(1));
        Assert.assertEquals("Integer 1 count", 2, f.getCount(Integer.valueOf(1)));
        Assert.assertEquals("Integer 1 count", 2, f.getCount(Long.valueOf(1)));
        Assert.assertEquals("Integer 1 cumPct", 0.5, f.getCumPct(1), TOLERANCE);
        Assert.assertEquals("Integer 1 cumPct", 0.5, f.getCumPct(Long.valueOf(1)), TOLERANCE);
        Assert.assertEquals("Integer 1 cumPct", 0.5, f.getCumPct(Integer.valueOf(1)), TOLERANCE);

        f.incrementValue(ONE, -2);
        f.incrementValue(THREE, 5);

        Assert.assertEquals("Integer 1 count", 0, f.getCount(1));
        Assert.assertEquals("Integer 3 count", 5, f.getCount(3));

        Iterator<?> it = f.valuesIterator();
        while (it.hasNext()) {
            Assert.assertTrue(it.next() instanceof Long);
        }
    }

    @Test
    public void testSerial() {
        f.addValue(ONE_LONG);
        f.addValue(TWO_LONG);
        f.addValue(ONE);
        f.addValue(TWO);
        Assert.assertEquals(f, TestUtils.serializeAndRecover(f));
    }

    @Test
    public void testGetUniqueCount() {
        Assert.assertEquals(0, f.getUniqueCount());
        f.addValue(ONE_LONG);
        Assert.assertEquals(1, f.getUniqueCount());
        f.addValue(ONE_LONG);
        Assert.assertEquals(1, f.getUniqueCount());
        f.addValue(TWO);
        Assert.assertEquals(2, f.getUniqueCount());
    }

    @Test
    public void testIncrement() {
        Assert.assertEquals(0, f.getUniqueCount());
        f.incrementValue(ONE_LONG, 1);
        Assert.assertEquals(1, f.getCount(ONE_LONG));

        f.incrementValue(ONE_LONG, 4);
        Assert.assertEquals(5, f.getCount(ONE_LONG));

        f.incrementValue(ONE_LONG, -5);
        Assert.assertEquals(0, f.getCount(ONE_LONG));

        try {
            f.incrementValue(CHAR_A, 1);
            Assert.fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }

        f = new Frequency();
        f.incrementValue(CHAR_A, 2);

        Assert.assertEquals(2, f.getCount(CHAR_A));

        try {
            f.incrementValue(ONE, 1);
            Assert.fail("Expecting IllegalArgumentException");
        } catch (IllegalArgumentException ex) {
            // expected
        }

        f.incrementValue(CHAR_A, 3);
        Assert.assertEquals(5, f.getCount(CHAR_A));

    }

    @Test
    public void testMerge() {
        Assert.assertEquals(0, f.getUniqueCount());
        f.addValue(ONE_LONG);
        f.addValue(TWO_LONG);
        f.addValue(ONE);
        f.addValue(TWO);

        Assert.assertEquals(2, f.getUniqueCount());
        Assert.assertEquals(2, f.getCount(ONE));
        Assert.assertEquals(2, f.getCount(TWO));

        Frequency g = new Frequency();
        g.addValue(ONE_LONG);
        g.addValue(THREE_LONG);
        g.addValue(THREE);

        Assert.assertEquals(2, g.getUniqueCount());
        Assert.assertEquals(1, g.getCount(ONE));
        Assert.assertEquals(2, g.getCount(THREE));

        f.merge(g);

        Assert.assertEquals(3, f.getUniqueCount());
        Assert.assertEquals(3, f.getCount(ONE));
        Assert.assertEquals(2, f.getCount(TWO));
        Assert.assertEquals(2, f.getCount(THREE));
    }

    @Test
    public void testMergeCollection() {
        Assert.assertEquals(0, f.getUniqueCount());
        f.addValue(ONE_LONG);

        Assert.assertEquals(1, f.getUniqueCount());
        Assert.assertEquals(1, f.getCount(ONE));
        Assert.assertEquals(0, f.getCount(TWO));

        Frequency g = new Frequency();
        g.addValue(TWO_LONG);

        Frequency h = new Frequency();
        h.addValue(THREE_LONG);

        List<Frequency> coll = new ArrayList<Frequency>();
        coll.add(g);
        coll.add(h);
        f.merge(coll);

        Assert.assertEquals(3, f.getUniqueCount());
        Assert.assertEquals(1, f.getCount(ONE));
        Assert.assertEquals(1, f.getCount(TWO));
        Assert.assertEquals(1, f.getCount(THREE));
    }

    @Test
    public void testMode() {
        List<Comparable<?>> mode;
        mode = f.getMode();
        Assert.assertEquals(0, mode.size());

        f.addValue("3");
        mode = f.getMode();
        Assert.assertEquals(1, mode.size());
        Assert.assertEquals("3", mode.get(0));

        f.addValue("2");
        mode = f.getMode();
        Assert.assertEquals(2, mode.size());
        Assert.assertEquals("2", mode.get(0));
        Assert.assertEquals("3",mode.get(1));

        f.addValue("2");
        mode = f.getMode();
        Assert.assertEquals(1, mode.size());
        Assert.assertEquals("2", mode.get(0));
        Assert.assertFalse(mode.contains("1"));
        Assert.assertTrue(mode.contains("2"));

        try {
            f.addValue(Double.valueOf(Double.NaN));
            Assert.fail("Expected MathIllegalArgumentException");
        } catch (MathIllegalArgumentException e) {
            // expected
        }
    }

    @Test
    public void testModeDoubleNan() {
        List<Comparable<?>> mode;
        f.addValue(Double.valueOf(Double.NaN));
        f.addValue(Double.valueOf(Double.NaN));
        f.addValue(Double.valueOf(Double.NaN));
        f.addValue(Double.valueOf(Double.NEGATIVE_INFINITY));
        f.addValue(Double.valueOf(Double.POSITIVE_INFINITY));
        f.addValue(Double.valueOf(Double.NEGATIVE_INFINITY));
        f.addValue(Double.valueOf(Double.POSITIVE_INFINITY));
        f.addValue(Double.valueOf(Double.NEGATIVE_INFINITY));
        f.addValue(Double.valueOf(Double.POSITIVE_INFINITY));
        mode = f.getMode();
        Assert.assertEquals(3, mode.size());
        Assert.assertEquals(Double.valueOf(Double.NEGATIVE_INFINITY), mode.get(0));
        Assert.assertEquals(Double.valueOf(Double.POSITIVE_INFINITY), mode.get(1));
        Assert.assertEquals(Double.valueOf(Double.NaN), mode.get(2));
        try {
            f.addValue(Float.valueOf(Float.NaN));
            Assert.fail("Expected MathIllegalArgumentException");
        } catch (MathIllegalArgumentException e) {
            // expected
        }
    }

    @Test
    public void testModeFloatNan() {
        List<Comparable<?>> mode;
        f.addValue(Float.valueOf(Float.NaN));
        f.addValue(Float.valueOf(Float.NaN));
        f.addValue(Float.valueOf(Float.NaN));
        f.addValue(Float.valueOf(Float.NEGATIVE_INFINITY));
        f.addValue(Float.valueOf(Float.POSITIVE_INFINITY));
        f.addValue(Float.valueOf(Float.NEGATIVE_INFINITY));
        f.addValue(Float.valueOf(Float.POSITIVE_INFINITY));
        f.addValue(Float.valueOf(Float.NEGATIVE_INFINITY));
        f.addValue(Float.valueOf(Float.POSITIVE_INFINITY));
        mode = f.getMode();
        Assert.assertEquals(3, mode.size());
        Assert.assertEquals(Float.valueOf(Float.NEGATIVE_INFINITY), mode.get(0));
        Assert.assertEquals(Float.valueOf(Float.POSITIVE_INFINITY), mode.get(1));
        Assert.assertEquals(Float.valueOf(Float.NaN), mode.get(2));
        try {
            f.addValue(Double.valueOf(Double.NaN));
            Assert.fail("Expected MathIllegalArgumentException");
        } catch (MathIllegalArgumentException e) {
            // expected
        }
    }

}