ChiSquaredDistribution Class

Represents a χ2 distribution.

Definition

Namespace: Meta.Numerics.Statistics.Distributions
Assembly: Meta.Numerics (in Meta.Numerics.dll) Version: 4.2.0+6d77d64445f7d5d91b12e331399c4362ecb25333
C#
public sealed class ChiSquaredDistribution : ContinuousDistribution
Inheritance
Object    UnivariateDistribution    ContinuousDistribution    ChiSquaredDistribution

Remarks

A chi squared distribution is an asymmetrical distribution ranging from zero to infinity with a peak near its number of degrees of freedom ν. It is a one-parameter distribution determined entirely by the parameter ν.

The figure above shows the χ2 distribution for ν = 6, as well as the normal distribution with equal mean and variance for reference.

The sum of the squares of ν independent standard-normal distributed variables is distributed as χ2 with ν degrees of freedom.

The χ2 distribution appears in least-squares fitting as the distribution of the sum-of-squared-deviations under the null hypothesis that the model explains the data. For example, the goodness-of-fit statistic returned by the model our model fitting methods (FitToFunction(FuncDouble, T, Double, Double), FitToLinearFunction(FuncT, Double), FitToLine, and others) follows a χ2 distribution.

Constructors

ChiSquaredDistribution Initializes a new χ2 distribution.

Properties

DegreesOfFreedom Gets the number of degrees of freedom ν of the distribution.
ExcessKurtosis Gets the excess kurtosis of the distribution.
(Overrides UnivariateDistributionExcessKurtosis)
Mean Gets the mean of the distribution.
(Overrides UnivariateDistributionMean)
Median Gets the median of the distribution.
(Overrides ContinuousDistributionMedian)
Skewness Gets the skewness of the distribution.
(Overrides UnivariateDistributionSkewness)
StandardDeviation Gets the standard deviation of the distribution.
(Inherited from UnivariateDistribution)
Support Gets the interval over which the distribution is non-vanishing.
(Overrides ContinuousDistributionSupport)
Variance Gets the variance of the distribution.
(Overrides UnivariateDistributionVariance)

Methods

CentralMoment Computes a central moment of the distribution.
(Overrides ContinuousDistributionCentralMoment(Int32))
Cumulant Computes a cumulant of the distribution.
(Overrides UnivariateDistributionCumulant(Int32))
EqualsDetermines whether the specified object is equal to the current object.
(Inherited from Object)
ExpectationValue Computes the expectation value of the given function.
(Inherited from ContinuousDistribution)
GetHashCodeServes as the default hash function.
(Inherited from Object)
GetRandomValue Generates a random variate.
(Inherited from ContinuousDistribution)
GetRandomValues Generates the given number of random variates.
(Inherited from ContinuousDistribution)
GetTypeGets the Type of the current instance.
(Inherited from Object)
Hazard Computes the hazard function.
(Inherited from ContinuousDistribution)
InverseLeftProbability Returns the point at which the cumulative distribution function attains a given value.
(Overrides ContinuousDistributionInverseLeftProbability(Double))
InverseRightProbability Returns the point at which the right probability function attains the given value.
(Inherited from ContinuousDistribution)
LeftProbability Returns the cumulative probability to the left of (below) the given point.
(Overrides ContinuousDistributionLeftProbability(Double))
ProbabilityDensity Returns the probability density at the given point.
(Overrides ContinuousDistributionProbabilityDensity(Double))
RawMoment Computes a raw moment of the distribution.
(Overrides ContinuousDistributionRawMoment(Int32))
RightProbability Returns the cumulative probability to the right of (above) the given point.
(Overrides ContinuousDistributionRightProbability(Double))
ToStringReturns a string that represents the current object.
(Inherited from Object)

See Also