Represents a chi-squared distribution.

Namespace: Extreme.Statistics.Distributions
Assembly: Extreme.Numerics (Extreme.Numerics)

Syntax

Visual Basic (Declaration)
Public Class ChiSquareDistribution _
	Inherits GammaDistribution
C#
public class ChiSquareDistribution : GammaDistribution
C++
public ref class ChiSquareDistribution : public GammaDistribution

Methods

IconTypeDescription
static memberDistributionFunction(Double, Int32)
Evaluates the cumulative distribution function (CDF) of this distribution for the specified value.
DistributionFunction(Double)
Returns the value of the cumulative probability distribution function.
Equals(Object)
Determines whether the specified Object is equal to the current Object.
Finalize()
Allows an Object to attempt to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection.
GetExpectedHistogram(Double[](), Double)
Gets a Histogram whose bins contain the expected number of samples for a given total number of samples.
GetExpectedHistogram(Double, Double, Int32, Double)
Gets a Histogram whose bins contain the expected number of samples for a given total number of samples.
GetHashCode()
Serves as a hash function for a particular type.
static memberGetRandomVariate(Random, Double)
Returns a single random variate from a chi square distribution with the specified degrees of freedom.
GetRandomVariate(Random)
Returns a random sample from the distribution.
GetRandomVariates(Random, Vector)
Fills a Vector with random numbers.
GetRandomVariates(Random, Double[]())
Fills a Double array with random numbers.
GetRandomVariates(Random, Double[](), Int32, Int32)
Fills a Double array with random numbers.
GetRandomVariates(Random, Vector, Int32, Int32)
Fills a Double array with random numbers.
GetType()
Gets the Type of the current instance.
static memberInverseDistributionFunction(Double, Double)
Returns the inverse of the DistributionFunction(Double, Int32).
InverseDistributionFunction(Double)
Returns the inverse of the DistributionFunction(Double).
MemberwiseClone()
Creates a shallow copy of the current Object.
Probability(Double, Double)
Returns the probability that a sample taken from the distribution lies inside the specified interval.
ProbabilityDensityFunction(Double)
Returns the value of the probability density function (PDF) of this distribution for the specified value.
SurvivorDistributionFunction(Double)
Evaluates the survivor distribution function (SDF) of this distribution for the specified value.
ToString()
Returns a String that represents the current Object.

Constructors

IconTypeDescription
ChiSquareDistributionNew(Double)
Constructs a new Chi Squared distribution.

Properties

IconTypeDescription
DegreesOfFreedom
Gets the degrees of freedom for this chi-square distribution.
InterQuartileRange
Returns the inter-quartile range of this distribution.
IsSymmetrical
Gets a value that indicates whether the distribution is known to be symmetrical around the mean.
Kurtosis
Gets the kurtosis of the distribution.
LocationParameter
Gets the location parameter for the distribution.
Mean
Gets the mean or expectation value of the distribution.
ScaleParameter
Gets the scale parameter for the distribution.
ShapeParameter
Gets the shape parameter for the distribution.
Skewness
Gets the skewness of the distribution.
StandardDeviation
Gets the standard deviation of the distribution.
Variance
Gets the variance of the distribution.

Remarks

The sum of the squares of n indepemdent normal variables with zero mean and unit variance has a chi-squared distribution with n degrees of freedom. This means it also describes the Variance of samples taken from a NormalDistribution.

From this last property, we can see the usefulness of the chi-squared distribution as a test of statistical significance. We can determine the likelihood of obtaining a sample that deviates from the expected value by a specified amount.

The sum of two or more variables that have a chi-squared distribution also has a chi-squared distribution. The number of degrees of freedom of the new distribution equals the sum of the degrees of freedom of the original distributions.

Inheritance Hierarchy