/*
* File: ProbabilityMassFunction.java
* Authors: Kevin R. Dixon
* Company: Sandia National Laboratories
* Project: Cognitive Foundry
*
* Copyright Jan 23, 2009, Sandia Corporation.
* Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
* license for use of this work by or on behalf of the U.S. Government.
* Export of this program may require a license from the United States
* Government. See CopyrightHistory.txt for complete details.
*
*/
package gov.sandia.cognition.statistics;
import gov.sandia.cognition.annotation.PublicationReference;
import gov.sandia.cognition.annotation.PublicationType;
/**
* The {@code ProbabilityMassFunction} interface defines the functionality of
* a probability mass function.
*
* A PMF has the following properties:
* - The domain is a countably finite set
* - The dependent values sum to 1.0
* - PMF(x) == "probability that a random variable takes value x"
* - PMF(x) >= 0.0 for all x
* - By consequence, PMF(x) <= 1.0 for all x
*
* @param <DataType> Value for the domain (x-axis, independent variable), may be
* something like an Integer, etc.
* @author Justin Basilico
* @since 2.0
*/
@PublicationReference(
author="Wikipedia",
title="Probability mass function",
type=PublicationType.WebPage,
year=2009,
url="http://en.wikipedia.org/wiki/Probability_mass_function"
)
public interface ProbabilityMassFunction<DataType>
extends ProbabilityFunction<DataType>,
DiscreteDistribution<DataType>
{
@Override
public ProbabilityMassFunction<DataType> getProbabilityFunction();
/**
* Gets the entropy of the values in the histogram.
*
* @return The entropy of the values in the histogram.
*/
public double getEntropy();
}