jidt/java/source/infodynamics/measures/continuous/EntropyCalculator.java

79 lines
2.9 KiB
Java
Executable File

/*
* Java Information Dynamics Toolkit (JIDT)
* Copyright (C) 2012, Joseph T. Lizier
*
* 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 infodynamics.measures.continuous;
/**
* Interface for implementations of
* entropy estimators on continuous univariate data
* (ie <code>double[]</code> arrays).
*
* <p>
* Usage of the child classes implementing this interface is intended to follow this paradigm:
* </p>
* <ol>
* <li>Construct the calculator;</li>
* <li>Set properties using {@link #setProperty(String, String)};</li>
* <li>Initialise the calculator {@link #initialise()};</li>
* <li>Provide the observations/samples for the calculator
* to set up the PDFs, using: {@link #setObservations(double[])};</li>
* <li>Compute the entropy using:
* {@link #computeAverageLocalOfObservations()};</li>
* <li>Return to step 2 or 3 to re-use the calculator on a new data set.</li>
* </ol>
*
* <p><b>References:</b><br/>
* <ul>
* <li>T. M. Cover and J. A. Thomas, 'Elements of Information
Theory' (John Wiley & Sons, New York, 1991).</li>
* </ul>
*
* @author Joseph Lizier (<a href="joseph.lizier at gmail.com">email</a>,
* <a href="http://lizier.me/joseph/">www</a>)
*/
public interface EntropyCalculator extends InfoMeasureCalculatorContinuous {
// TODO Add addObservations() methods for entropy calculator.
// It's currently in EntropyCalculatorMultivariate; bring in
// here when we make all univariate entropy calculators use their
// underlying multivariate form.
/**
* Sets the samples from which to compute the PDF for the entropy.
* Should only be called once, the last call contains the
* observations that are used (they are not accumulated).
*
* @param observations array of (univariate) samples
* @throws Exception
*/
public void setObservations(double observations[]) throws Exception;
/**
* Compute the local entropy values for each of the
* previously-supplied samples.
*
* <p>PDFs are computed using all of the previously supplied
* observations.</p>
*
* @return the array of local entropy values corresponding to each
* previously supplied observation.
*/
public double[] computeLocalOfPreviousObservations() throws Exception;
}