has.specials {pim}

Extract information from a pim.formula object

Description

This group of functions provides an easy way to extract the extra information saved in a pim.formula object. Take a look at the help page of pim.formula for more information.

Usage

has.specials(x)

## S4 method for signature 'pim.formula'
has.specials(x)

terms(x, ...)

## S4 method for signature 'pim.formula'
terms(x)

lhs(x)

## S4 method for signature 'pim.formula'
lhs(x)

Arguments

x

an object of the class pim.formula

...

arguments passed to other methods

Value

has.specials(): a single TRUE or FALSE value indicating whether the formula right-hand side contains any special functions.

terms(): the terms object of the pim.formula object

lhs(): an object of class call containing the left hand side of the formula as used in the pim.

See Also

the class pim.formula-class

response for extracting the pseudoresponse variable, model.matrix for extracting the design matrix of pseudo-observations, formula for extracting the pim.formula and penv for extracting the pim environment.

Examples

data("FEVData")
# Create the "model frame"
FEVenv <- new.pim.env(FEVData, compare="unique")

# create the formula and bind it to the pim.environment.
FEVform <- new.pim.formula(
  Age ~ I(L(Height) - R(Height))  ,
  FEVenv
)
lhs(FEVform)
has.specials(FEVform)
penv(FEVform)

FEVform2 <- new.pim.formula(
  FEV ~ Height*Sex,
  FEVenv
)

has.specials(FEVform2)
terms(FEVform2)