/*
* 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: 8034 $
*/
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 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: 8034 $");
}
}