Differential D1831 Diff 6171 java/server/src/main/java/org/softwareheritage/graph/utils/Statistics.java

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				package org.softwareheritage.graph.utils;

				import java.util.ArrayList;

				/**
				* Compute various statistics on a list of values.
				*
				* @author Thibault Allançon
				* @version 0.0.1
				* @since 0.0.1
				*/

				public class Statistics {
				/** Input values */
				ArrayList<Double> values;

				/**
				* Constructor.
				*
				* @param values input values
				*/
				public Statistics(ArrayList<Double> values) {
				this.values = values;
				}

				/**
				* Returns the minimum value.
				*
				* @return minimum value
				*/
				public double getMin() {
				double min = Double.POSITIVE_INFINITY;
				for (double v : values) {
				min = Math.min(min, v);
				}
				return min;
				}

				/**
				* Returns the maximum value.
				*
				* @return maximum value
				*/
				public double getMax() {
				double max = Double.NEGATIVE_INFINITY;
				for (double v : values) {
				max = Math.max(max, v);
				}
				return max;
				}

				/**
				* Computes the average.
				*
				* @return average value
				*/
				public double getAverage() {
				double sum = 0;
				for (double v : values) {
				sum += v;
				}
				return sum / (double) values.size();
				}

				/**
				* Computes the standard deviation.
				*
				* @return standard deviation value
				*/
				public double getStandardDeviation() {
				double average = getAverage();
				double variance = 0;
				for (double v : values) {
				variance += (v - average) * (v - average);
				}
				variance /= (double) values.size();
				return Math.sqrt(variance);
				}

				/**
				* Computes and prints all statistical values.
				*/
				public void printAll() {
				System.out.println("min value: " + getMin());
				System.out.println("max value: " + getMax());
				System.out.println("average: " + getAverage());
				System.out.println("standard deviation: " + getStandardDeviation());
				}
				}