Package org.tweetyproject.math.probability

Class ProbabilityFunction<T extends Comparable<T>>

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

  • Constructor Details

    • 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 Details

    • probability

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

    • probability

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

    • 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:
      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 Comparable<S>> ProbabilityFunction<S> convexCombination​(double[] factors, ProbabilityFunction<S>[] creators) throws 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:
      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 Comparable<S>> ProbabilityFunction<S> getUniformDistribution​(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​(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 String toString()
      Overrides:
      toString in class Object

    • clear

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

    • containsKey

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

    • containsValue

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

    • entrySet

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

    • get

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

    • isEmpty

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

    • put

      public Probability put​(T key, Probability value)
      Specified by:
      put in interface Map<T extends Comparable<T>,​Probability>

    • putAll

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

    • remove

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

    • size

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

    • values

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

    • keySet

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

    • hashCode

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

    • getProbabilityVector

      public 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 Vector<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​(Object obj)
      Specified by:
      equals in interface Map<T extends Comparable<T>,​Probability>
      Overrides:
      equals in class Object