samoa-api/src/main/java/com/yahoo/labs/samoa/moa/classifiers/core/driftdetection/ADWINChangeDetector.java

package com.yahoo.labs.samoa.moa.classifiers.core.driftdetection;

/*
 * #%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 com.github.javacliparser.FloatOption;
import com.yahoo.labs.samoa.moa.core.ObjectRepository;
import com.yahoo.labs.samoa.moa.tasks.TaskMonitor;

/**
 * Drift detection method based in ADWIN. ADaptive sliding WINdow is a change detector and estimator. It keeps a
 * variable-length window of recently seen items, with the property that the window has the maximal length statistically
 * consistent with the hypothesis "there has been no change in the average value inside the window".
 * 
 * 
 * @author Albert Bifet (abifet at cs dot waikato dot ac dot nz)
 * @version $Revision: 7 $
 */
public class ADWINChangeDetector extends AbstractChangeDetector {

  protected ADWIN adwin;

  public FloatOption deltaAdwinOption = new FloatOption("deltaAdwin", 'a',
      "Delta of Adwin change detection", 0.002, 0.0, 1.0);

  @Override
  public void input(double inputValue) {
    if (this.adwin == null) {
      resetLearning();
    }
    this.isChangeDetected = adwin.setInput(inputValue);
    this.isWarningZone = false;
    this.delay = 0.0;
    this.estimation = adwin.getEstimation();
  }

  @Override
  public void resetLearning() {
    adwin = new ADWIN(this.deltaAdwinOption.getValue());
  }

  @Override
  public void getDescription(StringBuilder sb, int indent) {
    // TODO Auto-generated method stub
  }

  @Override
  protected void prepareForUseImpl(TaskMonitor monitor,
      ObjectRepository repository) {
    // TODO Auto-generated method stub
  }
}