nlme: getCovariate.varFunc – R documentation

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getCovariate.varFunc

Extract varFunc Covariate

Description

This method function extracts the covariate(s) associated with the variance function represented by object, if any is present.

Usage

## S3 method for class 'varFunc'
getCovariate(object, form, data)

Arguments

`object`	an object inheriting from class `varFunc`, representing a variance function structure.
`form`	an optional formula specifying the covariate to be evaluated in `object`. Defaults to `formula(object)`.
`data`	some methods for this generic require a `data` object. Not used in this method.

Value

if object has a covariate attribute, its value is returned; else NULL is returned.

Author(s)

José Pinheiro and Douglas Bates bates@stat.wisc.edu

Examples

vf1 <- varPower(1.1, form = ~age)
covariate(vf1) <- Orthodont[["age"]]
getCovariate(vf1)

nlme

Linear and Nonlinear Mixed Effects Models

v3.1-152

GPL (>= 2) | file LICENCE

Authors

José Pinheiro [aut] (S version), Douglas Bates [aut] (up to 2007), Saikat DebRoy [ctb] (up to 2002), Deepayan Sarkar [ctb] (up to 2005), EISPACK authors [ctb] (src/rs.f), Siem Heisterkamp [ctb] (Author fixed sigma), Bert Van Willigen [ctb] (Programmer fixed sigma), Johannes Ranke [ctb] (varConstProp()), R-core [aut, cre]

Initial release

2021-02-03