Package net.sf.tweety.math.probability

Class ProbabilityFunction<T extends java.lang.Comparable<T>>

  • Type Parameters:
    T - The class of the objects used.
    All Implemented Interfaces:
    java.util.Map<T,​Probability>
    Direct Known Subclasses:
    ProbabilisticExtension, SubgraphProbabilityFunction
    public class ProbabilityFunction<T extends java.lang.Comparable<T>>
extends java.lang.Object
implements java.util.Map<T,​Probability>
    This class represents a probability distribution over some set of objects
    Author:
    Matthias Thimm

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.Map<T,​Probability> probabilities
      The probabilities of the objects.
      private static java.util.Random random
      For random sampling.

    • Method Summary

      Modifier and Type Method Description
      void clear()  
      boolean containsKey​(java.lang.Object key)  
      boolean containsValue​(java.lang.Object value)  
      static <S extends java.lang.Comparable<S>>
      ProbabilityFunction<S>      		 convexCombination​(double[] factors, ProbabilityFunction<S>[] creators)
      Computes the convex combination of the given probability distributions P1,...,PN with parameters factors, i.e.
      ProbabilityFunction<T> convexCombination​(double d, ProbabilityFunction<T> other)
      Computes the convex combination of this P1 and the given probability distribution P2 with parameter d, i.e.
      java.util.Set<java.util.Map.Entry<T,​Probability>> entrySet()  
      boolean equals​(java.lang.Object obj)  
      Probability get​(java.lang.Object key)  
      java.util.Vector<Probability> getProbabilityVector()
      Returns the vector of probabilities, depending on the order of the domain elements (which can be ordered as they implement Comparable).
      java.util.Vector<java.lang.Double> getProbabilityVectorAsDoubles()
      Returns the vector of probabilities, depending on the order of the domain elements (which can be ordered as they implement Comparable).
      static <S extends java.lang.Comparable<S>>
      ProbabilityFunction<S>      		 getUniformDistribution​(java.util.Set<S> objects)
      Returns the uniform distribution on the given interpretations.
      int hashCode()  
      boolean isEmpty()  
      boolean isNormalized()
      Checks whether this probability function is normalized, i.e.
      java.util.Set<T> keySet()  
      ProbabilityFunction<T> linearCombination​(double d1, double d2, ProbabilityFunction<T> other)
      Makes a linear combination of this distribution "p1" and the given distribution "other" and the given parameters, i.e.
      void normalize()
      Normalizes this probability function to have mass 1.
      protected static void normalize​(java.util.List<java.lang.Double> probabilities)
      Normalizes the given list of probabilities, i.e.
      Probability probability​(java.util.Collection<? extends T> objects)
      Gets the probability of the given object.
      Probability probability​(T w)
      Gets the probability of the given object.
      Probability put​(T key, Probability value)  
      void putAll​(java.util.Map<? extends T,​? extends Probability> m)  
      Probability remove​(java.lang.Object key)  
      T sample()
      Samples one element from the domain of this probability function, depending on its probability.
      T sample​(java.util.Random random)
      Samples one element from the domain of this probability function, depending on its probability.
      int size()  
      java.lang.String toString()  
      java.util.Collection<Probability> values()  

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Map

        compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

    • Field Detail

      • random

        private static java.util.Random random
        For random sampling.

      • probabilities

        private java.util.Map<T extends java.lang.Comparable<T>,​Probability> probabilities
        The probabilities of the objects.

    • Constructor Detail

      • ProbabilityFunction

        public ProbabilityFunction()
        Creates a new probability function.

      • ProbabilityFunction

        public ProbabilityFunction​(ProbabilityFunction<T> other)
        Creates a new probability function by copying the given one.
        Parameters:
        other - another probability function

    • Method Detail

      • probability

        public Probability probability​(T w)
                        throws java.lang.IllegalArgumentException
        Gets the probability of the given object.
        Parameters:
        w - some object.
        Returns:
        the probability of the given object.
        Throws:
        java.lang.IllegalArgumentException - if the given object has no probability

      • probability

        public Probability probability​(java.util.Collection<? extends T> objects)
                        throws java.lang.IllegalArgumentException
        Gets the probability of the given object.
        Parameters:
        objects - some object.
        Returns:
        the probability of the given object.
        Throws:
        java.lang.IllegalArgumentException - if the given object has no probability

      • normalize

        protected static void normalize​(java.util.List<java.lang.Double> probabilities)
        Normalizes the given list of probabilities, i.e. divides each probability by the sum of all probabilities.
        Parameters:
        probabilities - a list of probabilities

      • isNormalized

        public boolean isNormalized()
        Checks whether this probability function is normalized, i.e. the sum of all probabilities is 1.
        Returns:
        "true" if this probability function is normalized.

      • normalize

        public void normalize()
        Normalizes this probability function to have mass 1.

      • convexCombination

        public ProbabilityFunction<T> convexCombination​(double d,
                                                ProbabilityFunction<T> other)
        Computes the convex combination of this P1 and the given probability distribution P2 with parameter d, i.e. it returns a P with P(i)=d P1(i) + (1-d) P2(i) for every interpretation i.
        Parameters:
        d - a double
        other - a probability distribution
        Returns:
        the convex combination of this P1 and the given probability distribution P2 with parameter d.
        Throws:
        java.lang.IllegalArgumentException - if either d is not in [0,1] or this and the given probability distribution are not defined on the same set of interpretations.

      • linearCombination

        public ProbabilityFunction<T> linearCombination​(double d1,
                                                double d2,
                                                ProbabilityFunction<T> other)
        Makes a linear combination of this distribution "p1" and the given distribution "other" and the given parameters, i.e. it returns a P with P(i)=d1 P1(i) + d2 P2(i) for every interpretation i. NOTE: P is normalized after combination.
        Parameters:
        d1 - a double.
        d2 - a double.
        other - a probability distribution.
        Returns:
        a probability distribution.

      • convexCombination

        public static <S extends java.lang.Comparable<S>> ProbabilityFunction<S> convexCombination​(double[] factors,
                                                                                           ProbabilityFunction<S>[] creators)
                                                                                    throws java.lang.IllegalArgumentException
        Computes the convex combination of the given probability distributions P1,...,PN with parameters factors, i.e. it returns a P with P(i)=d1 P1(i) + d2 P2(i)+ ... + dN PN(i) for every object i (with d1,...,dN=factors).
        Type Parameters:
        S - The object class
        Parameters:
        factors - a vector of doubles.
        creators - a vector of probability distributions.
        Returns:
        the convex combination of the given distributions with parameters factors.
        Throws:
        java.lang.IllegalArgumentException - if either the sum of factors d is not in 1, or this and the given probability distributions are not defined on the same set of objects, or the lengths of creators and factors differ.

      • getUniformDistribution

        public static <S extends java.lang.Comparable<S>> ProbabilityFunction<S> getUniformDistribution​(java.util.Set<S> objects)
        Returns the uniform distribution on the given interpretations.
        Type Parameters:
        S - The interpretation class
        Parameters:
        objects - set of interpretations of type S.
        Returns:
        the uniform distribution on the given interpretations.

      • sample

        public T sample()
        Samples one element from the domain of this probability function, depending on its probability.
        Returns:
        a sample from this probability function.

      • sample

        public T sample​(java.util.Random random)
        Samples one element from the domain of this probability function, depending on its probability.
        Parameters:
        random - the number generator used.
        Returns:
        a sample from this probability function.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • clear

        public void clear()
        Specified by:
        clear in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • containsKey

        public boolean containsKey​(java.lang.Object key)
        Specified by:
        containsKey in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • containsValue

        public boolean containsValue​(java.lang.Object value)
        Specified by:
        containsValue in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • entrySet

        public java.util.Set<java.util.Map.Entry<T,​Probability>> entrySet()
        Specified by:
        entrySet in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • get

        public Probability get​(java.lang.Object key)
        Specified by:
        get in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • putAll

        public void putAll​(java.util.Map<? extends T,​? extends Probability> m)
        Specified by:
        putAll in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • remove

        public Probability remove​(java.lang.Object key)
        Specified by:
        remove in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • size

        public int size()
        Specified by:
        size in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • values

        public java.util.Collection<Probability> values()
        Specified by:
        values in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • keySet

        public java.util.Set<T> keySet()
        Specified by:
        keySet in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>

      • hashCode

        public int hashCode()
        Specified by:
        hashCode in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>
        Overrides:
        hashCode in class java.lang.Object

      • getProbabilityVector

        public java.util.Vector<Probability> getProbabilityVector()
        Returns the vector of probabilities, depending on the order of the domain elements (which can be ordered as they implement Comparable).
        Returns:
        the vector of probabilities

      • getProbabilityVectorAsDoubles

        public java.util.Vector<java.lang.Double> getProbabilityVectorAsDoubles()
        Returns the vector of probabilities, depending on the order of the domain elements (which can be ordered as they implement Comparable).
        Returns:
        the vector of probabilities as doubles

      • equals

        public boolean equals​(java.lang.Object obj)
        Specified by:
        equals in interface java.util.Map<T extends java.lang.Comparable<T>,​Probability>
        Overrides:
        equals in class java.lang.Object