R: Create a groupedData object from a matrix

balancedGrouped {nlme}

R Documentation

Create a groupedData object from a matrix

Description

Create a groupedData object from a data matrix. This function can be used only with balanced data. The opposite conversion, from a groupedData object to a matrix, is done with asTable.

Usage

balancedGrouped(form, data, labels=NULL, units=NULL)

Arguments

`form`	A formula of the form `y ~ x \| g` giving the name of the response, the primary covariate, and the grouping factor.
`data`	A matrix or data frame containing the values of the response grouped according to the levels of the grouping factor (rows) and the distinct levels of the primary covariate (columns). The `dimnames` of the matrix are used to construct the levels of the grouping factor and the primary covariate.
`labels`	an optional list of character strings giving labels for the response and the primary covariate. The label for the primary covariate is named `x` and that for the response is named `y`. Either label can be omitted.
`units`	an optional list of character strings giving the units for the response and the primary covariate. The units string for the primary covariate is named `x` and that for the response is named `y`. Either units string can be omitted.

Value

A balanced groupedData object.

Author(s)

José Pinheiro and Douglas Bates bates@stat.wisc.edu

References

Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S and S-PLUS, Springer, New York.

Examples

OrthoMat <- asTable( Orthodont )
Orth2 <- balancedGrouped(distance ~ age | Subject, data = OrthoMat,
    labels = list(x = "Age",
                  y = "Distance from pituitary to pterygomaxillary fissure"),
    units = list(x = "(yr)", y = "(mm)"))
Orth2[ 1:10, ]        ## check the first few entries

# Pinheiro and Bates, p. 109
ergoStool.mat <- asTable(ergoStool)
balancedGrouped(effort~Type|Subject,
                data=ergoStool.mat)

[Package nlme version 3.1-131 Index]