Represents Bartlett's test that a set of samples have the same variance.

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

Syntax

Visual Basic (Declaration)
Public NotInheritable Class BartlettTest _ Inherits MultiSampleTest

C#
public sealed class BartlettTest : MultiSampleTest

C++
public ref class BartlettTest sealed : public MultiSampleTest

Methods

Icon	Type	Description
	CalculateStatistic()	Calculates the value of the statistic used for this test.
	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.
	GetConfidenceInterval(Double)	Returns the confidence interval for the test parameter for the specified confidence level.
	GetHashCode()	Serves as a hash function for a particular type.
	GetLowerCriticalValue()	Gets the lower critical value for the hypothesis test's current significance level.
	GetLowerCriticalValue(Double)	Gets the lower critical value for the hypothesis test at the specified significance level.
	GetType()	Gets the Type of the current instance.
	GetUpperCriticalValue()	Gets the upper critical value for the test statistic at the hypothesis test's current significance level.
	GetUpperCriticalValue(Double)	Gets the upper critical value for the test statistic at the specified significance level.
	MemberwiseClone()	Creates a shallow copy of the current Object.
	Reject()	Returns a value that indicates whether the null hypothesis is rejected using the default significance level.
	Reject(Double)	Returns a value that indicates whether the null hypothesis is rejected using the specified significance level.
	ToString()	Returns a String that represents the current Object.

Constructors

Icon	Type	Description
	BartlettTestNew()	Constructs a new BartlettTest..
	BartlettTestNew(NumericalVariable[]())	Constructs a new BartlettTest for the specified NumericalVariable array.
	BartlettTestNew(VariableCollection)	Constructs a new BartlettTest for the specified NumericalVariable.

Properties

Icon	Type	Description
	DegreesOfFreedom	Gets the degrees of freedom for this chi-square distribution.
	Distribution	Sets the probability distribution used in the hypothesis test.
	HypothesisType	Gets or sets a value that indicates whether the test is one or two-tailed.
	PValue	Gets the probability that the test statistic would take on the calculated value under the null hypothesis.
	Samples	Gets the collection of samples for the test.
	SignificanceLevel	Gets the significance level used to test the null hypothesis.
	Statistic	Gets the value of the test statistic.

Remarks

Use the BartlettTest class to test the hypothesis that a number of samples have the same variance. This property is called homogeneity of variance.

Some statistical procedures, such as the AnovaModel, assume that variances are the same across groups.

Bartlett's test is a relatively fast test for homogeneity of variances. The test is based on the assumption that the samples are normally distributed. It is sensitive to violations of this assumption. In practical terms, this means that Bartlett's test cannot adequately distinguish between violation of homogeneity of variances and violation of the normality assumption. In such a case, LeveneTest gives more meaningful results.

Inheritance Hierarchy

System.Object
  Extreme.Statistics.Tests.HypothesisTest
    Extreme.Statistics.Tests.MultiSampleTest
      Extreme.Statistics.Tests.BartlettTest