/*
* 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 2 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* KernelEvaluation.java
* Copyright (C) 2006 University of Waikato, Hamilton, New Zealand
*/
package weka.classifiers.functions.supportVector;
import weka.core.Instances;
import weka.core.Option;
import weka.core.OptionHandler;
import weka.core.RevisionHandler;
import weka.core.RevisionUtils;
import weka.core.Utils;
import java.io.BufferedReader;
import java.io.FileReader;
import java.util.Enumeration;
/**
* Class for evaluating Kernels.
*
* @author fracpete (fracpete at waikato dot ac dot nz)
* @version $Revision: 1.3 $
*/
public class KernelEvaluation
implements RevisionHandler {
/** the result string */
protected StringBuffer m_Result;
/** the kernel evaluation results */
protected double[][] m_Evaluations;
/** the number of performed evaluations */
protected int m_NumEvals;
/** the number of cache hits */
protected int m_NumCacheHits;
/** user-supplied options */
protected String[] m_Options;
/**
* default constructor
*/
public KernelEvaluation() {
super();
m_Result = new StringBuffer();
m_Evaluations = new double[0][0];
m_Options = new String[0];
m_NumEvals = 0;
m_NumCacheHits = 0;
}
/**
* sets the option the user supplied for the kernel
*
* @param options options that were supplied for the kernel
*/
public void setUserOptions(String[] options) {
m_Options = (String[]) options.clone();
}
/**
* returns the options the user supplied for the kernel
*
* @return the user supplied options for the kernel
*/
public String[] getUserOptions() {
return (String[]) m_Options.clone();
}
/**
* Generates an option string to output on the commandline.
*
* @param Kernel the Kernel to generate the string for
* @return the option string
*/
protected static String makeOptionString(Kernel Kernel) {
StringBuffer text;
text = new StringBuffer();
// general options
text.append("\nGeneral options:\n\n");
text.append("-t <training file>\n");
text.append("\tThe name of the training file.\n");
text.append("-c <class index>\n");
text.append("\tSets index of class attribute (default: last).\n");
// Kernel specific options, if any
if (Kernel instanceof OptionHandler) {
text.append(
"\nOptions specific to "
+ Kernel.getClass().getName().replaceAll(".*\\.", "") + ":\n\n");
Enumeration enm = ((OptionHandler) Kernel).listOptions();
while (enm.hasMoreElements()) {
Option option = (Option) enm.nextElement();
text.append(option.synopsis() + "\n");
text.append(option.description() + "\n");
}
}
return text.toString();
}
/**
* Evaluates the Kernel with the given commandline options and returns
* the evaluation string.
*
* @param Kernel the Kernel to evaluate
* @param options the commandline options
* @return the generated output string
* @throws Exception if evaluation fails
*/
public static String evaluate(Kernel Kernel, String[] options)
throws Exception {
String trainFileString = "";
BufferedReader reader;
KernelEvaluation eval;
String classIndexString;
int classIndex = -1;
Instances train;
String[] userOptions;
// help?
if (Utils.getFlag('h', options))
throw new Exception("\nHelp requested.\n" + makeOptionString(Kernel));
try {
// general options
trainFileString = Utils.getOption('t', options);
if (trainFileString.length() == 0)
throw new Exception("No training file given!");
reader = new BufferedReader(new FileReader(trainFileString));
classIndexString = Utils.getOption('c', options);
if (classIndexString.length() != 0) {
if (classIndexString.equals("first"))
classIndex = 1;
else if (classIndexString.equals("last"))
classIndex = -1;
else
classIndex = Integer.parseInt(classIndexString);
}
// Kernel specific options
userOptions = (String[]) options.clone();
if (Kernel instanceof OptionHandler) {
((OptionHandler) Kernel).setOptions(options);
}
// left-over options?
Utils.checkForRemainingOptions(options);
}
catch (Exception e) {
throw new Exception(
"\nWeka exception: "
+ e.getMessage() + "\n"
+ makeOptionString(Kernel));
}
// load file and build kernel
eval = new KernelEvaluation();
eval.setUserOptions(userOptions);
train = new Instances(reader);
if (classIndex == -1)
train.setClassIndex(train.numAttributes() - 1);
else
train.setClassIndex(classIndex);
return eval.evaluate(Kernel, train);
}
/**
* Evaluates a kernel with the options given in an array of strings.
*
* @param kernelString class of kernel as a string
* @param options the array of string containing the options
* @throws Exception if model could not be evaluated successfully
* @return a string describing the results
*/
public static String evaluate(String kernelString, String[] options) throws Exception {
Kernel kernel;
// Create kernel
try {
kernel = (Kernel) Class.forName(kernelString).newInstance();
}
catch (Exception e) {
throw new Exception("Can't find class with name " + kernelString + '.');
}
return evaluate(kernel, options);
}
/**
* Evaluates the Kernel with the given commandline options and returns
* the evaluation string.
*
* @param kernel the Kernel to evaluate
* @param data the data to run the Kernel with
* @return the generated output string
* @throws Exception if evaluation fails
*/
public String evaluate(Kernel kernel, Instances data)
throws Exception {
long startTime;
long endTime;
int i;
int n;
m_Result = new StringBuffer();
// build kernel
startTime = System.currentTimeMillis();
kernel.buildKernel(data);
endTime = System.currentTimeMillis();
m_Result.append("\n=== Model ===\n\n");
if (Utils.joinOptions(getUserOptions()).trim().length() != 0)
m_Result.append("Options: " + Utils.joinOptions(getUserOptions()) + "\n\n");
m_Result.append(kernel.toString() + "\n");
// evaluate dataset
m_Evaluations = new double[data.numInstances()][data.numInstances()];
for (n = 0; n < data.numInstances(); n++) {
for (i = n; i < data.numInstances(); i++) {
m_Evaluations[n][i] = kernel.eval(n, i, data.instance(n));
}
}
// test cache for cached kernels
if (kernel instanceof CachedKernel) {
for (n = 0; n < data.numInstances(); n++) {
for (i = n; i < data.numInstances(); i++) {
m_Evaluations[n][i] = kernel.eval(n, i, data.instance(n));
}
}
}
m_NumEvals = kernel.numEvals();
m_NumCacheHits = kernel.numCacheHits();
// summary
m_Result.append("\n=== Evaluation ===\n\n");
if (kernel instanceof CachedKernel) {
m_Result.append("Cache size : " + ((CachedKernel) kernel).getCacheSize() + "\n");
}
m_Result.append("# Evaluations: " + m_NumEvals + "\n");
m_Result.append("# Cache hits : " + m_NumCacheHits + "\n");
m_Result.append("Elapsed time : " + (((double) (endTime - startTime)) / 1000) + "s\n");
return m_Result.toString();
}
/**
* Tests whether the current evaluation object is equal to another
* evaluation object
*
* @param obj the object to compare against
* @return true if the two objects are equal
*/
public boolean equals(Object obj) {
if ((obj == null) || !(obj.getClass().equals(this.getClass())))
return false;
KernelEvaluation cmp = (KernelEvaluation) obj;
if (m_NumEvals != cmp.m_NumEvals) return false;
if (m_NumCacheHits != cmp.m_NumCacheHits) return false;
if (m_Evaluations.length != cmp.m_Evaluations.length)
return false;
for (int n = 0; n < m_Evaluations.length; n++) {
for (int i = 0; i < m_Evaluations[n].length; i++) {
if (Double.isNaN(m_Evaluations[n][i]) && Double.isNaN(cmp.m_Evaluations[n][i]))
continue;
if (m_Evaluations[n][i] != cmp.m_Evaluations[n][i])
return false;
}
}
return true;
}
/**
* returns a summary string of the evaluation with a no title
*
* @return the summary string
*/
public String toSummaryString() {
return toSummaryString("");
}
/**
* returns a summary string of the evaluation with a default title
*
* @param title the title to print before the result
* @return the summary string
*/
public String toSummaryString(String title) {
StringBuffer result;
result = new StringBuffer(title);
if (title.length() != 0)
result.append("\n");
result.append(m_Result);
return result.toString();
}
/**
* returns the current result
*
* @return the currently stored result
* @see #toSummaryString()
*/
public String toString() {
return toSummaryString();
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 1.3 $");
}
/**
* A test method for this class. Just extracts the first command line
* argument as a kernel class name and calls evaluate.
*
* @param args an array of command line arguments, the first of which
* must be the class name of a kernel.
*/
public static void main(String[] args) {
try {
if (args.length == 0) {
throw new Exception(
"The first argument must be the class name of a kernel");
}
String kernel = args[0];
args[0] = "";
System.out.println(evaluate(kernel, args));
}
catch (Exception ex) {
ex.printStackTrace();
System.err.println(ex.getMessage());
}
}
}