Java tutorial
/* * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* * PerformanceStats.java * Copyright (C) 2007-2012 University of Waikato, Hamilton, New Zealand */ package weka.core.neighboursearch; import java.io.Serializable; import java.util.Enumeration; import java.util.Vector; import weka.core.AdditionalMeasureProducer; import weka.core.RevisionHandler; import weka.core.RevisionUtils; /** * The class that measures the performance of a nearest * neighbour search (NNS) algorithm. * * @author Ashraf M. Kibriya (amk14[at-the-rate]cs[dot]waikato[dot]ac[dot]nz) * @version $Revision$ */ public class PerformanceStats implements AdditionalMeasureProducer, Serializable, RevisionHandler { /** for serialization. */ private static final long serialVersionUID = -7215110351388368092L; /** The total number of queries looked at. */ protected int m_NumQueries; //Point-stats variables /** The min and max data points looked for a query by * the NNS algorithm. */ public double m_MinP, m_MaxP; /** The sum of data points looked * at for all the queries. */ public double m_SumP; /** The squared sum of data points looked * at for all the queries. */ public double m_SumSqP; /** The number of data points looked at * for the current/last query. */ public double m_PointCount; //Coord-stats variables /** The min and max coordinates(attributes) looked * at per query. */ public double m_MinC, m_MaxC; /** The sum of coordinates/attributes looked at * for all the queries. */ public double m_SumC; /** The squared sum of coordinates/attributes looked at * for all the queries. */ public double m_SumSqC; /** * The number of coordinates looked at for * the current/last query. */ public double m_CoordCount; /** * default constructor. */ public PerformanceStats() { reset(); } /** * Resets all internal fields/counters. */ public void reset() { m_NumQueries = 0; //point stats m_SumP = m_SumSqP = m_PointCount = 0; m_MinP = Integer.MAX_VALUE; m_MaxP = Integer.MIN_VALUE; //coord stats m_SumC = m_SumSqC = m_CoordCount = 0; m_MinC = Integer.MAX_VALUE; m_MaxC = Integer.MIN_VALUE; } /** * Signals start of the nearest neighbour search. * Initializes the stats object. */ public void searchStart() { m_PointCount = 0; m_CoordCount = 0; } /** * Signals end of the nearest neighbour search. * Calculates the statistics for the search. */ public void searchFinish() { m_NumQueries++; m_SumP += m_PointCount; m_SumSqP += m_PointCount * m_PointCount; if (m_PointCount < m_MinP) m_MinP = m_PointCount; if (m_PointCount > m_MaxP) m_MaxP = m_PointCount; //coord stats double coordsPerPt = m_CoordCount / m_PointCount; ; m_SumC += coordsPerPt; m_SumSqC += coordsPerPt * coordsPerPt; if (coordsPerPt < m_MinC) m_MinC = coordsPerPt; if (coordsPerPt > m_MaxC) m_MaxC = coordsPerPt; } /** * Increments the point count * (number of datapoints looked at). */ public void incrPointCount() { m_PointCount++; } /** * Increments the coordinate count * (number of coordinates/attributes * looked at). */ public void incrCoordCount() { m_CoordCount++; } /** * adds the given number to the point count. * * @param n The number to add to the point count. */ public void updatePointCount(int n) { m_PointCount += n; } /** * Returns the number of queries. * * @return The number of queries. */ public int getNumQueries() { return m_NumQueries; } /** * Returns the total number of points visited. * * @return The total number. */ public double getTotalPointsVisited() { return m_SumP; } /** * Returns the mean of points visited. * * @return The mean points visited. */ public double getMeanPointsVisited() { return m_SumP / (double) m_NumQueries; } /** * Returns the standard deviation of points visited. * * @return The standard deviation. */ public double getStdDevPointsVisited() { return Math.sqrt((m_SumSqP - (m_SumP * m_SumP) / (double) m_NumQueries) / (m_NumQueries - 1)); } /** * Returns the minimum of points visited. * * @return The minimum. */ public double getMinPointsVisited() { return m_MinP; } /** * Returns the maximum of points visited. * * @return The maximum. */ public double getMaxPointsVisited() { return m_MaxP; } /*************----------Coord Stat functions---------**************/ /** * Returns the total sum of coords per point. * * @return The total per point. */ public double getTotalCoordsPerPoint() { return m_SumC; } /** * Returns the mean of coords per point. * * @return The mean. */ public double getMeanCoordsPerPoint() { return m_SumC / (double) m_NumQueries; } /** * Returns the standard deviation of coords per point. * * @return The standard deviation. */ public double getStdDevCoordsPerPoint() { return Math.sqrt((m_SumSqC - (m_SumC * m_SumC) / (double) m_NumQueries) / (m_NumQueries - 1)); } /** * Returns the minimum of coords per point. * * @return The minimum. */ public double getMinCoordsPerPoint() { return m_MinC; } /** * Returns the maximum of coords per point. * * @return The maximum. */ public double getMaxCoordsPerPoint() { return m_MaxC; } /*****----MiscFunctions----****/ /** * Returns an enumeration of the additional measure names. * * @return An enumeration of the measure names. */ public Enumeration<String> enumerateMeasures() { Vector<String> newVector = new Vector<String>(); newVector.addElement("measureTotal_points_visited"); newVector.addElement("measureMean_points_visited"); newVector.addElement("measureStdDev_points_visited"); newVector.addElement("measureMin_points_visited"); newVector.addElement("measureMax_points_visited"); //coord stats newVector.addElement("measureTotalCoordsPerPoint"); newVector.addElement("measureMeanCoordsPerPoint"); newVector.addElement("measureStdDevCoordsPerPoint"); newVector.addElement("measureMinCoordsPerPoint"); newVector.addElement("measureMaxCoordsPerPoint"); return newVector.elements(); } /** * Returns the value of the named measure. * * @param additionalMeasureName The name of the measure to query for * its value. * @return The value of the named measure. * @throws IllegalArgumentException If the named measure is not * supported. */ public double getMeasure(String additionalMeasureName) throws IllegalArgumentException { if (additionalMeasureName.compareToIgnoreCase("measureTotal_points_visited") == 0) { return (double) getTotalPointsVisited(); } else if (additionalMeasureName.compareToIgnoreCase("measureMean_points_visited") == 0) { return (double) getMeanPointsVisited(); } else if (additionalMeasureName.compareToIgnoreCase("measureStdDev_points_visited") == 0) { return (double) getStdDevPointsVisited(); } else if (additionalMeasureName.compareToIgnoreCase("measureMin_points_visited") == 0) { return (double) getMinPointsVisited(); } else if (additionalMeasureName.compareToIgnoreCase("measureMax_points_visited") == 0) { return (double) getMaxPointsVisited(); } //coord stats else if (additionalMeasureName.compareToIgnoreCase("measureTotalCoordsPerPoint") == 0) { return (double) getTotalCoordsPerPoint(); } else if (additionalMeasureName.compareToIgnoreCase("measureMeanCoordsPerPoint") == 0) { return (double) getMeanCoordsPerPoint(); } else if (additionalMeasureName.compareToIgnoreCase("measureStdDevCoordsPerPoint") == 0) { return (double) getStdDevCoordsPerPoint(); } else if (additionalMeasureName.compareToIgnoreCase("measureMinCoordsPerPoint") == 0) { return (double) getMinCoordsPerPoint(); } else if (additionalMeasureName.compareToIgnoreCase("measureMaxCoordsPerPoint") == 0) { return (double) getMaxCoordsPerPoint(); } else { throw new IllegalArgumentException(additionalMeasureName + " not supported by PerformanceStats."); } } /** * Returns a string representation of the statistics. * * @return The statistics as string. */ public String getStats() { StringBuffer buf = new StringBuffer(); buf.append(" min, max, total, mean, stddev\n"); buf.append("Points: " + getMinPointsVisited() + ", " + getMaxPointsVisited() + "," + getTotalPointsVisited() + "," + getMeanPointsVisited() + ", " + getStdDevPointsVisited() + "\n"); return buf.toString(); } /** * Returns the revision string. * * @return the revision */ public String getRevision() { return RevisionUtils.extract("$Revision$"); } }