Extract Data Frame Covariate

The right hand side of form, stripped of any conditioning expression (i.e. an expression following a | operator), is evaluated in object.

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

Arguments

object

an object inheriting from class data.frame.

form

an optional formula specifying the covariate to be evaluated in object. Defaults to formula(object).

data

some methods for this generic require a separate data frame. Not used in this method.

Value

the value of the right hand side of form, stripped of any conditional expression, evaluated in object.

Author

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

See also

getCovariateFormula

Examples

getCovariate(Orthodont)
#>   [1]  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8
#>  [26] 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10
#>  [51] 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12
#>  [76] 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14  8 10 12 14
#> [101]  8 10 12 14  8 10 12 14