dfidx: model.frame.dfidx – R documentation

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model.frame.dfidx

model.frame/matrix for dfidx objects

Description

Specific model.frame/matrix are provided for dfidx objects. This leads to an unusual order of arguments compared to the usage. Actually, the first two arguments of the model.frame method are a dfidx and a formula and the only main argument of the model.matrix is a dfidx which should be the result of a call to the model.frame method, i.e. it should have a term attribute.

Usage

## S3 method for class 'dfidx'
model.frame(
  formula,
  data = NULL,
  ...,
  lhs = NULL,
  rhs = NULL,
  dot = "previous",
  alt.subset = NULL,
  reflevel = NULL,
  balanced = FALSE
)

## S3 method for class 'dfidx'
model.matrix(object, ..., lhs = NULL, rhs = 1, dot = "separate")

Arguments

`formula`	a `dfidx`
`data`	a `formula`
`..., lhs, rhs, dot`	see the `Formula` method
`alt.subset`	a subset of levels for the second index
`reflevel`	a user-defined first level for the second index
`balanced`	a boolean indicating if the resulting data.frame has to be balanced or not
`object`	a dfidx object

Value

a dfidx object for the model.frame method and a matrix for the model.matrix method.

Author(s)

Yves Croissant

Examples

data("TravelMode", package = "AER")
TM <- dfidx(TravelMode)
mf <- model.frame(TM, choice ~ vcost | income - 1 | travel)
head(model.matrix(mf, rhs = 1))
head(model.matrix(mf, rhs = 2))
head(model.matrix(mf, rhs = 1:3))

dfidx

Indexed Data Frames

v0.0-4

GPL (>= 2)

Authors

Yves Croissant [aut, cre]

Initial release

2021-02-02