Class EnumeratedIntegerDistribution
- java.lang.Object
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- org.hipparchus.distribution.discrete.AbstractIntegerDistribution
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- org.hipparchus.distribution.discrete.EnumeratedIntegerDistribution
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- All Implemented Interfaces:
Serializable
,IntegerDistribution
public class EnumeratedIntegerDistribution extends AbstractIntegerDistribution
Implementation of an integer-valuedEnumeratedDistribution
.Values with zero-probability 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:
- Serialized Form
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Constructor Summary
Constructors Constructor Description EnumeratedIntegerDistribution(int[] data)
Create a discrete integer-valued distribution from the input data.EnumeratedIntegerDistribution(int[] singletons, double[] probabilities)
Create a discrete distribution using the given probability mass function definition.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description double
cumulativeProbability(int x)
For a random variableX
whose values are distributed according to this distribution, this method returnsP(X <= x)
.double
getNumericalMean()
Use this method to get the numerical value of the mean of this distribution.double
getNumericalVariance()
Use this method to get the numerical value of the variance of this distribution.List<Pair<Integer,Double>>
getPmf()
Return the probability mass function as a list of (value, probability) pairs.int
getSupportLowerBound()
Access the lower bound of the support.int
getSupportUpperBound()
Access the upper bound of the support.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.double
probability(int x)
For a random variableX
whose values are distributed according to this distribution, this method returnsP(X = x)
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Methods inherited from class org.hipparchus.distribution.discrete.AbstractIntegerDistribution
inverseCumulativeProbability, logProbability, probability, solveInverseCumulativeProbability
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Constructor Detail
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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
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EnumeratedIntegerDistribution
public EnumeratedIntegerDistribution(int[] data)
Create a discrete integer-valued 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
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Method Detail
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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
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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
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getNumericalMean
public double getNumericalMean()
Use this method to get the numerical value of the mean of this distribution.- Returns:
sum(singletons[i] * probabilities[i])
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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])
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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 non-zero probability.inf {x in Z | P(X <= x) > 0}
.- Returns:
- the lowest value with non-zero probability.
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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 non-zero probability.inf {x in R | P(X <= x) = 1}
.- Returns:
- the highest value with non-zero probability.
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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
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