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)

Jose Pinheiro Jose.Pinheiro@pharma.novartis.com 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.

### See Also

`groupedData`

, `isBalanced`

, `asTable`

### 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 3.1-80

Index]