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

package de.ugoe.cs.cpdp.training;

import weka.classifiers.AbstractClassifier;
import weka.classifiers.Classifier;
import weka.core.Capabilities;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.Utils;
import weka.core.Capabilities.Capability;

/**
 * Simple classifier that always predicts the same class
 * 
 * @author Steffen Herbold
 */
public class FixClass extends AbstractClassifier implements ITrainingStrategy, IWekaCompatibleTrainer {

        private static final long serialVersionUID = 1L;

        private double fixedClassValue = 0.0d;

        /**
         * Returns default capabilities of the classifier.
         * 
         * @return the capabilities of this classifier
         */
        @Override
        public Capabilities getCapabilities() {
                Capabilities result = super.getCapabilities();
                result.disableAll();

                // attributes
                result.enable(Capability.NOMINAL_ATTRIBUTES);
                result.enable(Capability.NUMERIC_ATTRIBUTES);
                result.enable(Capability.DATE_ATTRIBUTES);
                result.enable(Capability.STRING_ATTRIBUTES);
                result.enable(Capability.RELATIONAL_ATTRIBUTES);
                result.enable(Capability.MISSING_VALUES);

                // class
                result.enable(Capability.NOMINAL_CLASS);
                result.enable(Capability.NUMERIC_CLASS);
                result.enable(Capability.MISSING_CLASS_VALUES);

                // instances
                result.setMinimumNumberInstances(0);

                return result;
        }

        @Override
        public void setOptions(String[] options) throws Exception {
                fixedClassValue = Double.parseDouble(Utils.getOption('C', options));
        }

        @Override
        public double classifyInstance(Instance instance) {
                return fixedClassValue;
        }

        @Override
        public void buildClassifier(Instances traindata) throws Exception {
                // do nothing
        }

        @Override
        public void setParameter(String parameters) {
                try {
                        this.setOptions(parameters.split(" "));
                } catch (Exception e) {
                        e.printStackTrace();
                }               
        }

        @Override
        public void apply(Instances traindata) {
                // do nothing!
        }

        @Override
        public String getName() {
                return "FixClass";
        }

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

}