model.frame.dfidx: model.frame and model.matrix methods for dfidx objects

In dfidx: Indexed Data Frames

model.frame and model.matrix methods for dfidx objects

Description

Specific model.frame and model.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 method is a dfidx which should be the result of a call to the model.frame method, i.e. it should have a terms 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")

## S3 method for class 'dfidx_matrix'
print(x, ..., n = NULL)

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
x	a model matrix
n	the number of lines to print

Value

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

Author(s)

Yves Croissant

Examples

mn <- dfidx(munnell)
mf <- model.frame(mn, gsp ~ privatecap | publiccap + utilities | unemp + labor)
model.matrix(mf, rhs = 1)
model.matrix(mf, rhs = 2)
model.matrix(mf, rhs = 1:3)

dfidx documentation built on Aug. 8, 2025, 7:10 p.m.