model.matrix.reStruct {nlme} | R Documentation |

## reStruct Model Matrix

### Description

The model matrices for each element of `formula(object)`

,
calculated using `data`

, are bound together column-wise. When
multiple grouping levels are present (i.e. when ```
length(object) >
1
```

), the individual model matrices are combined from innermost (at
the leftmost position) to outermost (at the rightmost position).

### Usage

## S3 method for class 'reStruct':
model.matrix(object, data, contrast, ...)

### Arguments

`object` |
an object inheriting from class `reStruct` ,
representing a random effects structure and consisting of a list of
`pdMat` objects. |

`data` |
a data frame in which to evaluate the variables defined in
`formula(object)` . |

`contrast` |
an optional named list specifying the contrasts to be used
for representing the `factor` variables in `data` . The
components names should match the names of the variables in
`data` for which the contrasts are to be specified. The
components of this list will be used as the `contrasts`
attribute of the corresponding factor. If missing, the default
contrast specification is used. |

`...` |
some methods for this generic require additional
arguments. None are used in this method. |

### Value

a matrix obtained by binding together, column-wise, the model matrices
for each element of `formula(object)`

.

### Author(s)

Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu

### See Also

`model.matrix`

, `contrasts`

,
`reStruct`

, `formula.reStruct`

### Examples

rs1 <- reStruct(list(Dog = ~day, Side = ~1), data = Pixel)
model.matrix(rs1, Pixel)

[Package

*nlme* version 3.1-57

Index]