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    1   /*
    2    * Copyright 2004 The Apache Software Foundation.
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  package org.apache.commons.math.stat.descriptive;
    17
    18  import java.io.Serializable;
    19  import org.apache.commons.math.util.MathUtils;
    20
    21  /***
    22   *  Value object representing the results of a univariate statistical summary.
    23   *
    24   * @version $Revision: 348519 $ $Date: 2005-11-23 12:12:18 -0700 (Wed, 23 Nov 2005) $
    25   */
    26  public class StatisticalSummaryValues implements Serializable,
    27      StatisticalSummary {
    28
    29      /*** Serialization id */
    30      private static final long serialVersionUID = -5108854841843722536L;
    31
    32      /*** The sample mean */
    33      private final double mean;
    34
    35      /*** The sample variance */
    36      private final double variance;
    37
    38      /*** The number of observations in the sample */
    39      private final long n;
    40
    41      /*** The maximum value */
    42      private final double max;
    43
    44      /*** The minimum value */
    45      private final double min;
    46
    47      /*** The sum of the sample values */
    48      private final double sum;
    49
    50      /***
    51        * Constructor
    52        *
    53        * @param mean  the sample mean
    54        * @param variance  the sample variance
    55        * @param n  the number of observations in the sample
    56        * @param max  the maximum value
    57        * @param min  the minimum value
    58        * @param sum  the sum of the values
    59       */
    60      public StatisticalSummaryValues(double mean, double variance, long n,
    61          double max, double min, double sum) {
    62          super();
    63          this.mean = mean;
    64          this.variance = variance;
    65          this.n = n;
    66          this.max = max;
    67          this.min = min;
    68          this.sum = sum;
    69      }
    70
    71      /***
    72       * @return Returns the max.
    73       */
    74      public double getMax() {
    75          return max;
    76      }
    77
    78      /***
    79       * @return Returns the mean.
    80       */
    81      public double getMean() {
    82          return mean;
    83      }
    84
    85      /***
    86       * @return Returns the min.
    87       */
    88      public double getMin() {
    89          return min;
    90      }
    91
    92      /***
    93       * @return Returns the number of values.
    94       */
    95      public long getN() {
    96          return n;
    97      }
    98
    99      /***
    100      * @return Returns the sum.
    101      */
    102     public double getSum() {
    103         return sum;
    104     }
    105
    106     /***
    107      * @return Returns the standard deviation
    108      */
    109     public double getStandardDeviation() {
    110         return Math.sqrt(variance);
    111     }
    112
    113     /***
    114      * @return Returns the variance.
    115      */
    116     public double getVariance() {
    117         return variance;
    118     }
    119
    120     /***
    121      * Returns true iff <code>object</code> is a
    122      * <code>StatisticalSummaryValues</code> instance and all statistics have
    123      *  the same values as this.
    124      *
    125      * @param object the object to test equality against.
    126      * @return true if object equals this
    127      */
    128     public boolean equals(Object object) {
    129         if (object == this ) {
    130             return true;
    131         }
    132         if (object instanceof StatisticalSummaryValues == false) {
    133             return false;
    134         }
    135         StatisticalSummaryValues stat = (StatisticalSummaryValues) object;
    136         return (MathUtils.equals(stat.getMax(), this.getMax()) &&
    137                 MathUtils.equals(stat.getMean(),this.getMean()) &&
    138                 MathUtils.equals(stat.getMin(),this.getMin()) &&
    139                 MathUtils.equals(stat.getN(), this.getN()) &&
    140                 MathUtils.equals(stat.getSum(), this.getSum()) &&
    141                 MathUtils.equals(stat.getVariance(),this.getVariance()));
    142     }
    143
    144     /***
    145      * Returns hash code based on values of statistics
    146      *
    147      * @return hash code
    148      */
    149     public int hashCode() {
    150         int result = 31 + MathUtils.hash(getMax());
    151         result = result * 31 + MathUtils.hash(getMean());
    152         result = result * 31 + MathUtils.hash(getMin());
    153         result = result * 31 + MathUtils.hash(getN());
    154         result = result * 31 + MathUtils.hash(getSum());
    155         result = result * 31 + MathUtils.hash(getVariance());
    156         return result;
    157     }
    158
    159 }