Class EnumeratedIntegerDistribution
java.lang.Object
org.hipparchus.distribution.discrete.AbstractIntegerDistribution
org.hipparchus.distribution.discrete.EnumeratedIntegerDistribution
 All Implemented Interfaces:
Serializable
,IntegerDistribution
Implementation of an integervalued
EnumeratedDistribution
.
Values with zeroprobability are allowed but they do not extend the support.
Duplicate values are allowed. Probabilities of duplicate values are combined when computing cumulative probabilities and statistics.
 See Also:

Constructor Summary
ConstructorDescriptionEnumeratedIntegerDistribution
(int[] data) Create a discrete integervalued distribution from the input data.EnumeratedIntegerDistribution
(int[] singletons, double[] probabilities) Create a discrete distribution using the given probability mass function definition. 
Method Summary
Modifier and TypeMethodDescriptiondouble
cumulativeProbability
(int x) For a random variableX
whose values are distributed according to this distribution, this method returnsP(X <= x)
.double
Use this method to get the numerical value of the mean of this distribution.double
Use this method to get the numerical value of the variance of this distribution.getPmf()
Return the probability mass function as a list of (value, probability) pairs.int
Access the lower bound of the support.int
Access the upper bound of the support.boolean
Use this method to get information about whether the support is connected, i.e.double
probability
(int x) For a random variableX
whose values are distributed according to this distribution, this method returnsP(X = x)
.Methods inherited from class org.hipparchus.distribution.discrete.AbstractIntegerDistribution
inverseCumulativeProbability, logProbability, probability, solveInverseCumulativeProbability

Constructor Details

EnumeratedIntegerDistribution
public EnumeratedIntegerDistribution(int[] singletons, double[] probabilities) throws MathIllegalArgumentException Create a discrete distribution using the given probability mass function definition. Parameters:
singletons
 array of random variable values.probabilities
 array of probabilities. Throws:
MathIllegalArgumentException
 ifsingletons.length != probabilities.length
MathIllegalArgumentException
 if probabilities contains negative, infinite or NaN values or only 0's

EnumeratedIntegerDistribution
public EnumeratedIntegerDistribution(int[] data) Create a discrete integervalued distribution from the input data. Values are assigned mass based on their frequency. For example, [0,1,1,2] as input creates a distribution with values 0, 1 and 2 having probability masses 0.25, 0.5 and 0.25 respectively, Parameters:
data
 input dataset


Method Details

probability
public double probability(int x) For a random variableX
whose values are distributed according to this distribution, this method returnsP(X = x)
. In other words, this method represents the probability mass function (PMF) for the distribution. Parameters:
x
 the point at which the PMF is evaluated Returns:
 the value of the probability mass function at
x

cumulativeProbability
public double cumulativeProbability(int x) For a random variableX
whose values are distributed according to this distribution, this method returnsP(X <= x)
. In other words, this method represents the (cumulative) distribution function (CDF) for this distribution. Parameters:
x
 the point at which the CDF is evaluated Returns:
 the probability that a random variable with this
distribution takes a value less than or equal to
x

getNumericalMean
public double getNumericalMean()Use this method to get the numerical value of the mean of this distribution. Returns:
sum(singletons[i] * probabilities[i])

getNumericalVariance
public double getNumericalVariance()Use this method to get the numerical value of the variance of this distribution. Returns:
sum((singletons[i]  mean) ^ 2 * probabilities[i])

getSupportLowerBound
public int getSupportLowerBound()Access the lower bound of the support. This method must return the same value asinverseCumulativeProbability(0)
. In other words, this method must return
Returns the lowest value with nonzero probability.inf {x in Z  P(X <= x) > 0}
. Returns:
 the lowest value with nonzero probability.

getSupportUpperBound
public int getSupportUpperBound()Access the upper bound of the support. This method must return the same value asinverseCumulativeProbability(1)
. In other words, this method must return
Returns the highest value with nonzero probability.inf {x in R  P(X <= x) = 1}
. Returns:
 the highest value with nonzero probability.

isSupportConnected
public boolean isSupportConnected()Use this method to get information about whether the support is connected, i.e. whether all integers between the lower and upper bound of the support are included in the support. The support of this distribution is connected. Returns:
true

getPmf
Return the probability mass function as a list of (value, probability) pairs. Returns:
 the probability mass function.
