source: trunk/CrossPare/src/de/ugoe/cs/cpdp/training/WekaBaseTraining.java @ 39

package de.ugoe.cs.cpdp.training;

import java.util.Arrays;
import java.util.logging.Level;

import de.ugoe.cs.util.console.Console;

import weka.core.OptionHandler;
import weka.classifiers.Classifier;
import weka.classifiers.meta.CVParameterSelection;

/**
 * WekaBaseTraining2
 * 
 * Allows specification of the Weka classifier and its params in the XML experiment configuration.
 * 
 * Important conventions of the XML format: 
 * Cross Validation params always come last and are prepended with -CVPARAM
 * Example: <trainer name="WekaTraining" param="RandomForestLocal weka.classifiers.trees.RandomForest -CVPARAM I 5 25 5"/>
 */
public abstract class WekaBaseTraining implements IWekaCompatibleTrainer {
        
        protected Classifier classifier = null;
        protected String classifierClassName;
        protected String classifierName;
        protected String[] classifierParams;
        
        @Override
        public void setParameter(String parameters) {
                String[] params = parameters.split(" ");

                // first part of the params is the classifierName (e.g. SMORBF)
                classifierName = params[0];
                
                // the following parameters can be copied from weka!
                
                // second param is classifierClassName (e.g. weka.classifiers.functions.SMO)
                classifierClassName = params[1];
        
                // rest are params to the specified classifier (e.g. -K weka.classifiers.functions.supportVector.RBFKernel)
                classifierParams = Arrays.copyOfRange(params, 2, params.length);
                
                classifier = setupClassifier();
        }

        @Override
        public Classifier getClassifier() {
                return classifier;
        }

        public Classifier setupClassifier() {
                Classifier cl = null;
                try{
                        @SuppressWarnings("rawtypes")
                        Class c = Class.forName(classifierClassName);
                        Classifier obj = (Classifier) c.newInstance();
                        
                        // Filter out -CVPARAM, these are special because they do not belong to the Weka classifier class as parameters
                        String[] param = Arrays.copyOf(classifierParams, classifierParams.length);
                        String[] cvparam = {};
                        boolean cv = false;
                        for ( int i=0; i < classifierParams.length; i++ ) {
                                if(classifierParams[i].equals("-CVPARAM")) {
                                        // rest of array are cvparam
                                        cvparam = Arrays.copyOfRange(classifierParams, i+1, classifierParams.length);
                                        
                                        // before this we have normal params
                                        param = Arrays.copyOfRange(classifierParams, 0, i);
                                        
                                        cv = true;
                                        break;
                                }
                        }
                        
                        // set classifier params
                        ((OptionHandler)obj).setOptions(param);
                        cl = obj;
                        
                        // we have cross val params
                        // cant check on cvparam.length here, it may not be initialized                 
                        if(cv) {
                                final CVParameterSelection ps = new CVParameterSelection();
                                ps.setClassifier(obj);
                                ps.setNumFolds(5);
                                //ps.addCVParameter("I 5 25 5");
                                for( int i=1 ; i<cvparam.length/4 ; i++ ) {
                                        ps.addCVParameter(Arrays.asList(Arrays.copyOfRange(cvparam, 0, 4*i)).toString().replaceAll(", ", " ").replaceAll("^\\[|\\]$", ""));
                                }
                                
                                cl = ps;
                        }

                }catch(ClassNotFoundException e) {
                        Console.traceln(Level.WARNING, String.format("class not found: %s", e.toString()));
                        e.printStackTrace();
                } catch (InstantiationException e) {
                        Console.traceln(Level.WARNING, String.format("Instantiation Exception: %s", e.toString()));
                        e.printStackTrace();
                } catch (IllegalAccessException e) {
                        Console.traceln(Level.WARNING, String.format("Illegal Access Exception: %s", e.toString()));
                        e.printStackTrace();
                } catch (Exception e) {
                        Console.traceln(Level.WARNING, String.format("Exception: %s", e.toString()));
                        e.printStackTrace();
                }
                
                return cl;
        }

        @Override
        public String getName() {
                return classifierName;
        }
        
}