AdaptiveRandomForest-master/src/main/java/moa/classifiers/core/driftdetection/AbstractChangeDetector.java
/*
 *    AbstractChangeDetector.java
 *    Copyright (C) 2011 University of Waikato, Hamilton, New Zealand
 *    @author Albert Bifet (abifet at cs dot waikato dot ac dot nz)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package moa.classifiers.core.driftdetection;

import moa.options.AbstractOptionHandler;

/**
 * Abstract Change Detector. All change detectors in MOA extend this class.
 *
 * @author Albert Bifet (abifet at cs dot waikato dot ac dot nz)
 * @version $Revision: 7 $
 */
public abstract class AbstractChangeDetector extends AbstractOptionHandler
        implements ChangeDetector {



    /**
     * Change was detected
     */
    protected boolean isChangeDetected;

    /**
     * Warning Zone: after a warning and before a change 
     */
    protected boolean isWarningZone;

    /**
     * Prediction for the next value based in previous seen values
     */
    protected double estimation;

    /**
     * Delay in detecting change
     */
    protected double delay;

    /**
     * The change detector has been initialized with the option values
     */
    protected boolean isInitialized;

    /**
     * Resets this change detector. It must be similar to starting a new change
     * detector from scratch.
     *
     */
    public void resetLearning() {
        this.isChangeDetected = false;
        this.isWarningZone = false;
        this.estimation = 0.0;
        this.delay = 0.0;
        this.isInitialized = false;
    }

    /**
     * Adding a numeric value to the change detector<br><br>
     *
     * The output of the change detector is modified after the insertion of a
     * new item inside.
     *
     * @param inputValue the number to insert into the change detector
     */
    public abstract void input(double inputValue);

    /**
     * Gets whether there is change detected.
     *
     * @return true if there is change
     */
    public boolean getChange() {
        return this.isChangeDetected;
    }

    /**
     * Gets whether the change detector is in the warning zone, after a warning
     * alert and before a change alert.
     *
     * @return true if the change detector is in the warning zone
     */
    public boolean getWarningZone() {
        return this.isWarningZone;
    }

    /**
     * Gets the prediction of next values.
     *
     * @return a prediction of the next value
     */
    public double getEstimation() {
        return this.estimation;
    }

    /**
     * Gets the length of the delay in the change detected.
     *
     * @return he length of the delay in the change detected
     */
    public double getDelay() {
        return this.delay;
    }

    /**
     * Gets the output state of the change detection.
     *
     * @return an array with the number of change detections, number of
     * warnings, delay, and estimation.
     */
    public double[] getOutput() {
        double[] res = {this.isChangeDetected ? 1 : 0, this.isWarningZone ? 1 : 0, this.delay, this.estimation};
        return res;
    }

    /**
     * Returns a string representation of the model.
     *
     * @param out	the stringbuilder to add the description
     * @param indent	the number of characters to indent
     */
    @Override
    public abstract void getDescription(StringBuilder sb, int indent);

    /**
     * Produces a copy of this change detector method
     *
     * @return the copy of this change detector method
     */
    @Override
    public ChangeDetector copy() {
        return (ChangeDetector) super.copy();
    }
}