Documentation

manova

Class:RepeatedMeasuresModel

Multivariate analysis of variance

Syntax

manovatbl = manova(rm)
manovatbl = manova(rm,Name,Value)
[manovatbl,A,C,D] = manova(___)

Description

example

manovatbl= manova(rm)returns the results of multivariate analysis of variance (manova) for the repeated measures modelrm.

example

manovatbl= manova(rm,Name,Value)also returns manova results with additional options, specified by one or moreName,Valuepair arguments.

example

[manovatbl,A,C,D] = manova(___)also returns arraysA,C, andDfor the hypotheses tests of the formA*B*C = D, whereDis zero.

Input Arguments

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Repeated measures model, returned as aRepeatedMeasuresModel对象。

For properties and methods of this object, seeRepeatedMeasuresModel.

Name-Value Pair Arguments

Specify optional comma-separated pairs ofName,Valuearguments.Nameis the argument name andValueis the corresponding value.Namemust appear inside single quotes (' '). You can specify several name and value pair arguments in any order asName1,Value1,...,NameN,ValueN.

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Model specifying the within-subjects hypothesis test, specified as one of the following:

  • 'separatemeans'— Compute a separate mean for each group, and test for equality among the means.

  • Model specification — This is a model specification in the within-subject factors. Test each term in the model. In this case,tblcontains a separate manova for each term in the formula, with the multivariate response equal to the vector of coefficients of that term.

  • Anr-by-ncmatrix,C, specifyingnccontrasts among therrepeated measures. IfYrepresents the matrix of repeated measures you use in the repeated measures modelrm, then the outputtblcontains a separate manova for each column ofY*C.

Example:“WithinModel”,'separatemeans'

Single between-subjects factor, specified as the comma-separated pair consisting of'By'and a character vector.manovaperforms a separate test of the within-subjects model for each value of this factor.

For example, if you have a between-subjects factor, Drug, then you can specify that factor to perform manova as follows.

Example:“通过”、“药物”

Output Arguments

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Results of multivariate analysis of variance for the repeated measures modelrm, returned as atable.

manovauses these methods to measure the contributions of the model terms to the overall covariance:

  • Wilks' Lambda

  • Pillai's trace

  • Hotelling-Lawley trace

  • Roy's maximum root statistic

For details, seeMultivariate Analysis of Variance for Repeated Measures.

manovareturns the results for these tests for each group.manovatblcontains the following columns.

Column Name Definition
Within Within-subject terms
Between Between-subject terms
Statistic Name of the statistic computed
Value Value of the corresponding statistic
F F-statistic value
RSquare Measure for variance explained
df1 Numerator degrees of freedom
df2 Denominator degrees of freedom
pValue p-value for the correspondingF-statistic value

Data Types:table

Specification based on the between-subjects model, returned as a matrix or a cell array. It permits the hypothesis on the elements within given columns ofB(within time hypothesis). Ifmanovatblcontains multiple hypothesis tests,Amight be a cell array.

Data Types:single|double|cell

Specification based on the within-subjects model, returned as a matrix or a cell array. It permits the hypotheses on the elements within given rows ofB(between time hypotheses). Ifmanovatblcontains multiple hypothesis tests,Cmight be a cell array.

Data Types:single|double|cell

Hypothesis value, returned as 0.

Examples

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Load the sample data.

loadfisheriris

The column vectorspeciesconsists of iris flowers of three different species: setosa, versicolor, virginica. The double matrixmeasconsists of four types of measurements on the flowers: the length and width of sepals and petals in centimeters, respectively.

Store the data in a table array.

t = table(species,meas(:,1),meas(:,2),meas(:,3),meas(:,4),...'VariableNames',{'species','meas1','meas2','meas3','meas4'}); Meas = table([1 2 3 4]','VariableNames',{'Measurements'});

Fit a repeated measures model where the measurements are the responses and the species is the predictor variable.

rm = fitrm(t,'meas1-meas4~species','WithinDesign',Meas);

执行变量的多变量分析iance.

manova(rm)
ans = 8×9表统计价值之间在F RSquare df1 df2 pValue ________ ___________ _________ _________ ______ _______ ___ ___ ___________ Constant (Intercept) Pillai 0.99013 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Wilks 0.0098724 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Hotelling 100.29 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Roy 100.29 4847.5 0.99013 3 145 3.7881e-145 Constant species Pillai 0.96909 45.749 0.48455 6 292 2.4729e-39 Constant species Wilks 0.041153 189.92 0.79714 6 290 2.3958e-97 Constant species Hotelling 23.051 555.17 0.92016 6 288 4.6662e-155 Constant species Roy 23.04 1121.3 0.9584 3 146 1.4771e-100

执行多元一个ova separately for each species.

manova(rm,'By','species')
ans = 12×9 table Within Between Statistic Value F RSquare df1 df2 pValue ________ __________________ _________ ________ ______ _______ ___ ___ ___________ Constant species=setosa Pillai 0.9823 2682.7 0.9823 3 145 9.0223e-127 Constant species=setosa Wilks 0.017698 2682.7 0.9823 3 145 9.0223e-127 Constant species=setosa Hotelling 55.504 2682.7 0.9823 3 145 9.0223e-127 Constant species=setosa Roy 55.504 2682.7 0.9823 3 145 9.0223e-127 Constant species=versicolor Pillai 0.97 1562.8 0.97 3 145 3.7058e-110 Constant species=versicolor Wilks 0.029999 1562.8 0.97 3 145 3.7058e-110 Constant species=versicolor Hotelling 32.334 1562.8 0.97 3 145 3.7058e-110 Constant species=versicolor Roy 32.334 1562.8 0.97 3 145 3.7058e-110 Constant species=virginica Pillai 0.97261 1716.1 0.97261 3 145 5.1113e-113 Constant species=virginica Wilks 0.027394 1716.1 0.97261 3 145 5.1113e-113 Constant species=virginica Hotelling 35.505 1716.1 0.97261 3 145 5.1113e-113 Constant species=virginica Roy 35.505 1716.1 0.97261 3 145 5.1113e-113

Load the sample data.

loadfisheriris

The column vectorspeciesconsists of iris flowers of three different species: setosa, versicolor, virginica. The double matrixmeasconsists of four types of measurements on the flowers: the length and width of sepals and petals in centimeters, respectively.

Store the data in a table array.

t = table(species,meas(:,1),meas(:,2),meas(:,3),meas(:,4),...'VariableNames',{'species','meas1','meas2','meas3','meas4'}); Meas = dataset([1 2 3 4]','VarNames',{'Measurements'});

Fit a repeated measures model where the measurements are the responses and the species is the predictor variable.

rm = fitrm(t,'meas1-meas4~species','WithinDesign',Meas);

执行变量的多变量分析iance. Also return the arrays for constructing the hypothesis test.

[manovatbl,A,C,D] = manova(rm)
manovatbl = 8×9 table Within Between Statistic Value F RSquare df1 df2 pValue ________ ___________ _________ _________ ______ _______ ___ ___ ___________ Constant (Intercept) Pillai 0.99013 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Wilks 0.0098724 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Hotelling 100.29 4847.5 0.99013 3 145 3.7881e-145 Constant (Intercept) Roy 100.29 4847.5 0.99013 3 145 3.7881e-145 Constant species Pillai 0.96909 45.749 0.48455 6 292 2.4729e-39 Constant species Wilks 0.041153 189.92 0.79714 6 290 2.3958e-97 Constant species Hotelling 23.051 555.17 0.92016 6 288 4.6662e-155 Constant species Roy 23.04 1121.3 0.9584 3 146 1.4771e-100 A = 2×1 cell array [1×3 double] [2×3 double] C = 1 0 0 -1 1 0 0 -1 1 0 0 -1 D = 0

Index into matrix A.

A{1}
ans = 1 0 0
A{2}
ans = 0 1 0 0 0 1

Tips

  • The multivariate response for each observation (subject) is the vector of repeated measures.

  • To test a more general hypothesisA*B*C = D, usecoeftest.

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