manova5050 {ffmanova}R Documentation

Computation of 50-50 MANOVA results

Description

The function takes a design-with-responses object created by xy_Obj and produces 50-50 MANOVA output. Results are produced for each term in the model.

Usage

manova5050(xyObj, stand)

Arguments

xyObj design-with-responses object
stand standardisation of responses (0 or 1)

Details

Classical multivariate ANOVA (MANOVA) are useless in many practical cases. The tests perform poorly in cases with several highly correlated responses and the method collapses when the number of responses exceeds the number of observations. 50-50 MANOVA is made to handle this problem. Principal component analysis (PCA) is an important part of this methodology. Each test is based on a separate PCA.

Value

A list with components

termNames model term names
exVarSS explained variances calculated from sums of squares summed over all responses
df degrees of freedom - adjusted for other terms in model
df_om degrees of freedom - adjusted for terms contained in actual term
nPC number of principal components used for testing
nBU number of principal components used as buffer components
exVarPC variance explained by nPC components
exVarBU variance explained by (nPC+nBU) components
pValues 50-50 MANOVA p-values
stand logical. Whether the responses are standardised.

Note

The 50-50 MANOVA p-values are based on the Hotelling-Lawley Trace Statistic. The number of components for testing and the number of buffer components are chosen according to default rules.

Author(s)

Øyvind Langsrud and Bjørn-Helge Mevik

References

Langsrud, Ø. (2002) Rotation Tests. The Statistician, 51, 305–317.

See Also

ffmanova


[Package ffmanova version 0.1-1.1 Index]