    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.math3.stat.descriptive;
    018
    019    import java.io.Serializable;
    020
    021    import org.apache.commons.math3.util.FastMath;
    022    import org.apache.commons.math3.util.MathUtils;
    023    import org.apache.commons.math3.util.Precision;
    024
    025    /**
    026     *  Value object representing the results of a univariate statistical summary.
    027     *
    028     * @version $Id: StatisticalSummaryValues.java 1416643 2012-12-03 19:37:14Z tn $
    029     */
    030    public class StatisticalSummaryValues implements Serializable,
    031        StatisticalSummary {
    032
    033        /** Serialization id */
    034        private static final long serialVersionUID = -5108854841843722536L;
    035
    036        /** The sample mean */
    037        private final double mean;
    038
    039        /** The sample variance */
    040        private final double variance;
    041
    042        /** The number of observations in the sample */
    043        private final long n;
    044
    045        /** The maximum value */
    046        private final double max;
    047
    048        /** The minimum value */
    049        private final double min;
    050
    051        /** The sum of the sample values */
    052        private final double sum;
    053
    054        /**
    055          * Constructor
    056          *
    057          * @param mean  the sample mean
    058          * @param variance  the sample variance
    059          * @param n  the number of observations in the sample
    060          * @param max  the maximum value
    061          * @param min  the minimum value
    062          * @param sum  the sum of the values
    063         */
    064        public StatisticalSummaryValues(double mean, double variance, long n,
    065            double max, double min, double sum) {
    066            super();
    067            this.mean = mean;
    068            this.variance = variance;
    069            this.n = n;
    070            this.max = max;
    071            this.min = min;
    072            this.sum = sum;
    073        }
    074
    075        /**
    076         * @return Returns the max.
    077         */
    078        public double getMax() {
    079            return max;
    080        }
    081
    082        /**
    083         * @return Returns the mean.
    084         */
    085        public double getMean() {
    086            return mean;
    087        }
    088
    089        /**
    090         * @return Returns the min.
    091         */
    092        public double getMin() {
    093            return min;
    094        }
    095
    096        /**
    097         * @return Returns the number of values.
    098         */
    099        public long getN() {
    100            return n;
    101        }
    102
    103        /**
    104         * @return Returns the sum.
    105         */
    106        public double getSum() {
    107            return sum;
    108        }
    109
    110        /**
    111         * @return Returns the standard deviation
    112         */
    113        public double getStandardDeviation() {
    114            return FastMath.sqrt(variance);
    115        }
    116
    117        /**
    118         * @return Returns the variance.
    119         */
    120        public double getVariance() {
    121            return variance;
    122        }
    123
    124        /**
    125         * Returns true iff <code>object</code> is a
    126         * <code>StatisticalSummaryValues</code> instance and all statistics have
    127         *  the same values as this.
    128         *
    129         * @param object the object to test equality against.
    130         * @return true if object equals this
    131         */
    132        @Override
    133        public boolean equals(Object object) {
    134            if (object == this ) {
    135                return true;
    136            }
    137            if (object instanceof StatisticalSummaryValues == false) {
    138                return false;
    139            }
    140            StatisticalSummaryValues stat = (StatisticalSummaryValues) object;
    141            return Precision.equalsIncludingNaN(stat.getMax(),      getMax())  &&
    142                   Precision.equalsIncludingNaN(stat.getMean(),     getMean()) &&
    143                   Precision.equalsIncludingNaN(stat.getMin(),      getMin())  &&
    144                   Precision.equalsIncludingNaN(stat.getN(),        getN())    &&
    145                   Precision.equalsIncludingNaN(stat.getSum(),      getSum())  &&
    146                   Precision.equalsIncludingNaN(stat.getVariance(), getVariance());
    147        }
    148
    149        /**
    150         * Returns hash code based on values of statistics
    151         *
    152         * @return hash code
    153         */
    154        @Override
    155        public int hashCode() {
    156            int result = 31 + MathUtils.hash(getMax());
    157            result = result * 31 + MathUtils.hash(getMean());
    158            result = result * 31 + MathUtils.hash(getMin());
    159            result = result * 31 + MathUtils.hash(getN());
    160            result = result * 31 + MathUtils.hash(getSum());
    161            result = result * 31 + MathUtils.hash(getVariance());
    162            return result;
    163        }
    164
    165        /**
    166         * Generates a text report displaying values of statistics.
    167         * Each statistic is displayed on a separate line.
    168         *
    169         * @return String with line feeds displaying statistics
    170         */
    171        @Override
    172        public String toString() {
    173            StringBuffer outBuffer = new StringBuffer();
    174            String endl = "\n";
    175            outBuffer.append("StatisticalSummaryValues:").append(endl);
    176            outBuffer.append("n: ").append(getN()).append(endl);
    177            outBuffer.append("min: ").append(getMin()).append(endl);
    178            outBuffer.append("max: ").append(getMax()).append(endl);
    179            outBuffer.append("mean: ").append(getMean()).append(endl);
    180            outBuffer.append("std dev: ").append(getStandardDeviation())
    181                .append(endl);
    182            outBuffer.append("variance: ").append(getVariance()).append(endl);
    183            outBuffer.append("sum: ").append(getSum()).append(endl);
    184            return outBuffer.toString();
    185        }
    186
    187    }