/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

package org.apache.samoa.evaluation;

import org.apache.samoa.instances.Instance;
import org.apache.samoa.moa.MOAObject;
import org.apache.samoa.moa.core.Measurement;
import org.apache.samoa.moa.core.Vote;

/**
 * Interface implemented by learner evaluators to monitor the results of the learning process.
 * 
 * @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 * @version $Revision: 7 $
 */
public interface PerformanceEvaluator extends MOAObject {

  /**
   * Resets this evaluator. It must be similar to starting a new evaluator from scratch.
   * 
   */
  public void reset();

  /**
   * Adds a learning result to this evaluator.
   * 
   * @param inst
   *          the instance to be classified
   * @param classVotes
   *          an array containing the estimated membership probabilities of the test instance in each class
   * @return an array of measurements monitored in this evaluator
   */
  public void addResult(Instance inst, double[] classVotes, String instanceIdentifier,
          long delay);

  /**
   * Gets the current measurements monitored by this evaluator.
   * 
   * @return an array of measurements monitored by this evaluator
   */
  public Measurement[] getPerformanceMeasurements();

  /**
   * Gets the current votes monitored by this evaluator.
   * 
   * @return an array of votes monitored by this evaluator
   */
  public Vote[] getPredictionVotes();
}