nauf_model.matrix: Create a fixed effects model matrix using 'nauf' contrasts.

In CDEager/nauf: Regression with NA Values in Unordered Factors

Description

nauf_model.matrix creates a model matrix which employs nauf_contrasts for unordered factors.

Usage

nauf_model.matrix(object = NULL, data = NULL, ...)

Arguments

object	A nauf.frame or a regression formula. See 'Details'.
data	A nauf.frame or a data.frame containing the variables in object if object is a regression formula. See 'Details'.
...	Further arguments to be passed to nauf_model.frame when object is a regression formula and data is a data.frame. See 'Details'.

Details

Exactly what happens depends on the values of object and data. The following possibilities are evaluated in the order listed:

object is a nauf.frame

All arguments besides object are ignored, and the information in object is used to create the model matrix.

data is a nauf.frame

All arguments besides data are ignored, and the information in data is used to create the model matrix.

object is a formula and data is a data.frame

nauf_model.frame is called with formula = object and data = data, passing along any additional arguments in ... (including ncs_scale). Then the model matrix is created using the information in the resulting nauf.frame.

any other argument values

An error is returned.

Value

A fixed effects model matrix that implements nauf_contrasts. Unlike the default model.matrix method, the model matrix does not have a contrasts attribute, since multiple sets of contrasts may be required for some unordered factors.

See Also

nauf_contrasts for a description of the contrasts applied to unordered factors, nauf_model.frame for creating a model frame with nauf contrasts, and nauf_glFormula for obtaining both fixed effects and random effects model matrices.

Examples

dat <- plosives
dat$spont[dat$dialect == "Valladolid"] <- NA
form <- intdiff ~ voicing * dialect * spont +
  (1 + voicing * spont | speaker) + (1 + dialect | item)
sobj <- standardize(form, dat)
mf <- nauf_model.frame(sobj$formula, sobj$data)

## the following all result in the same model matrix
mm1 <- nauf_model.matrix(mf)
mm2 <- nauf_model.matrix(form, mf)  # 'form' ignored
mm3 <- nauf_model.matrix(sobj$formula, sobj$data)

CDEager/nauf documentation built on May 6, 2019, 9:24 a.m.