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Gamma Class

Continuous Univariate Gamma distribution. For details about this distribution, see Wikipedia - Gamma distribution.
Inheritance Hierarchy
SystemObject
  Altaxo.Calc.DistributionsGamma

Namespace: Altaxo.Calc.Distributions
Assembly: AltaxoCore (in AltaxoCore.dll) Version: 4.8.3179.0 (4.8.3179.0)
Syntax
C#
public class Gamma : IContinuousDistribution, IUnivariateDistribution, 
	IDistribution

The Gamma type exposes the following members.

Constructors
 NameDescription
Public methodGamma(Double, Double) Initializes a new instance of the Gamma class.
Public methodGamma(Double, Double, Random) Initializes a new instance of the Gamma class.
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Properties
 NameDescription
Public propertyEntropy Gets the entropy of the Gamma distribution.
Public propertyMaximum Gets the maximum of the Gamma distribution.
Public propertyMean Gets the mean of the Gamma distribution.
Public propertyMedian Gets the median of the Gamma distribution.
Public propertyMinimum Gets the minimum of the Gamma distribution.
Public propertyMode Gets the mode of the Gamma distribution.
Public propertyRandomSource Gets or sets the random number generator which is used to draw random samples.
Public propertyRate Gets or sets the rate or inverse scale (β) of the Gamma distribution. Range: β ≥ 0.
Public propertyScale Gets or sets the scale (θ) of the Gamma distribution.
Public propertyShape Gets or sets the shape (k, α) of the Gamma distribution. Range: α ≥ 0.
Public propertySkewness Gets the skewness of the Gamma distribution.
Public propertyStdDev Gets the standard deviation of the Gamma distribution.
Public propertyVariance Gets the variance of the Gamma distribution.
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Methods
 NameDescription
Public methodStatic memberCDF Computes the cumulative distribution (CDF) of the distribution at x, i.e. P(X ≤ x).
Public methodCumulativeDistribution Computes the cumulative distribution (CDF) of the distribution at x, i.e. P(X ≤ x).
Public methodDensity Computes the probability density of the distribution (PDF) at x, i.e. ∂P(X ≤ x)/∂x.
Public methodDensityLn Computes the log probability density of the distribution (lnPDF) at x, i.e. ln(∂P(X ≤ x)/∂x).
Public methodEqualsDetermines whether the specified object is equal to the current object.
(Inherited from Object)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.
(Inherited from Object)
Public methodGetHashCodeServes as the default hash function.
(Inherited from Object)
Public methodGetTypeGets the Type of the current instance.
(Inherited from Object)
Public methodStatic memberInvCDF Computes the inverse of the cumulative distribution function (InvCDF) for the distribution at the given probability. This is also known as the quantile or percent point function.
Public methodInverseCumulativeDistribution Computes the inverse of the cumulative distribution function (InvCDF) for the distribution at the given probability. This is also known as the quantile or percent point function.
Public methodStatic memberIsValidParameterSet Tests whether the provided values are valid parameters for this distribution.
Protected methodMemberwiseCloneCreates a shallow copy of the current Object.
(Inherited from Object)
Public methodStatic memberPDF Computes the probability density of the distribution (PDF) at x, i.e. ∂P(X ≤ x)/∂x.
Public methodStatic memberPDFLn Computes the log probability density of the distribution (lnPDF) at x, i.e. ln(∂P(X ≤ x)/∂x).
Public methodSample Generates a sample from the Gamma distribution.
Public methodStatic memberSample(Double, Double) Generates a sample from the Gamma distribution.
Public methodStatic memberSample(Random, Double, Double) Generates a sample from the Gamma distribution.
Public methodSamples Generates a sequence of samples from the Gamma distribution.
Public methodSamples(Double) Fills an array with samples generated from the distribution.
Public methodStatic memberSamples(Double, Double) Generates a sequence of samples from the Gamma distribution.
Public methodStatic memberSamples(Double, Double, Double) Fills an array with samples generated from the distribution.
Public methodStatic memberSamples(Random, Double, Double) Generates a sequence of samples from the Gamma distribution.
Public methodStatic memberSamples(Random, Double, Double, Double) Fills an array with samples generated from the distribution.
Public methodToString A string representation of the distribution.
(Overrides ObjectToString)
Public methodStatic memberWithShapeRate Constructs a Gamma distribution from a shape and inverse scale parameter. The distribution will be initialized with the default random number generator.
Public methodStatic memberWithShapeScale Constructs a Gamma distribution from a shape and scale parameter. The distribution will be initialized with the default random number generator.
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Remarks
The Gamma distribution is parametrized by a shape and inverse scale parameter. When we want to specify a Gamma distribution which is a point distribution we set the shape parameter to be the location of the point distribution and the inverse scale as positive infinity. The distribution with shape and inverse scale both zero is undefined. Random number generation for the Gamma distribution is based on the algorithm in: "A Simple Method for Generating Gamma Variables" - Marsaglia & Tsang ACM Transactions on Mathematical Software, Vol. 26, No. 3, September 2000, Pages 363–372.
See Also