Extract pdBlocked Formula

Usage

formula(object, asList)

Arguments

object an object inheriting from class code{pdBlocked}, representing a positive definite block diagonal matrix.
asList an optional logical value. If TRUE, a list with the formulas for the individual block diagonal elements of object is returned; else, if FALSE, a one-sided formula combining all individual formulas is returned. Defaults to FALSE.

Description

The formula attributes of the pdMat elements of object are extracted and returned as a list, in case asList=TRUE, or converted to a single one-sided formula when asList=FALSE. If the pdMat elements do not have a formula attribute, a NULL value is returned.

Value

a list of one-sided formulas, or a single one-sided formula, or NULL.

Author(s)

Jose Pinheiro and Douglas Bates

See Also

pdBlocked, pdMat

Examples

library(lme)
pd1 <- pdBlocked(list(~ age, ~ Sex - 1))
formula(pd1)
formula(pd1, asList = TRUE)

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