samoa-api/src/main/java/org/apache/samoa/moa/classifiers/rules/core/voting/AbstractErrorWeightedVote.java

package org.apache.samoa.moa.classifiers.rules.core.voting;

/*
 * #%L
 * SAMOA
 * %%
 * Copyright (C) 2014 - 2015 Apache Software Foundation
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import java.util.ArrayList;
import java.util.List;

import org.apache.samoa.moa.AbstractMOAObject;

/**
 * AbstractErrorWeightedVote class for weighted votes based on estimates of errors.
 * 
 * @author Joao Duarte (jmduarte@inescporto.pt)
 * @version $Revision: 1 $
 */
public abstract class AbstractErrorWeightedVote extends AbstractMOAObject implements ErrorWeightedVote {
  /**
	 * 
	 */
  private static final long serialVersionUID = -7340491298217227675L;
  protected List<double[]> votes;
  protected List<Double> errors;
  protected double[] weights;

  public AbstractErrorWeightedVote() {
    super();
    votes = new ArrayList<double[]>();
    errors = new ArrayList<Double>();
  }

  public AbstractErrorWeightedVote(AbstractErrorWeightedVote aewv) {
    super();
    votes = new ArrayList<double[]>();
    for (double[] vote : aewv.votes) {
      double[] v = new double[vote.length];
      for (int i = 0; i < vote.length; i++)
        v[i] = vote[i];
      votes.add(v);
    }
    errors = new ArrayList<Double>();
    for (Double db : aewv.errors) {
      errors.add(db.doubleValue());
    }
    if (aewv.weights != null) {
      weights = new double[aewv.weights.length];
      for (int i = 0; i < aewv.weights.length; i++)
        weights[i] = aewv.weights[i];
    }
  }

  @Override
  public void addVote(double[] vote, double error) {
    votes.add(vote);
    errors.add(error);
  }

  @Override
  abstract public double[] computeWeightedVote();

  @Override
  public double getWeightedError()
  {
    double weightedError = 0;
    if (weights != null && weights.length == errors.size())
    {
      for (int i = 0; i < weights.length; ++i)
        weightedError += errors.get(i) * weights[i];
    }
    else
      weightedError = -1;
    return weightedError;
  }

  @Override
  public double[] getWeights() {
    return weights;
  }

  @Override
  public int getNumberVotes() {
    return votes.size();
  }
}