R: Interpret a GAM formula

interpret.gam {mgcv}

R Documentation

Interpret a GAM formula

Description

This is an internal function of package mgcv. It is a service routine for gam which splits off the strictly parametric part of the model formula, returning it as a formula, and interprets the smooth parts of the model formula.

Not normally called directly.

Usage

interpret.gam(gf, extra.special = NULL)

Arguments

`gf`	A GAM formula as supplied to `gam` or `gamm`, or a list of such formulae, as supplied for some `gam` families.
`extra.special`	Name of any extra special in formula in addition to `s`, `te`, `ti` and `t2`.

Value

An object of class split.gam.formula with the following items:

`pf`	A model formula for the strictly parametric part of the model.
`pfok`	TRUE if there is a `pf` formula.
`smooth.spec`	A list of class `xx.smooth.spec` objects where `xx` depends on the basis specified for the term. (These can be passed to smooth constructor method functions to actually set up penalties and bases.)
`full.formula`	An expanded version of the model formula in which the options are fully expanded, and the options do not depend on variables which might not be available later.
`fake.formula`	A formula suitable for use in evaluating a model frame.
`response`	Name of the response variable.

Author(s)

Simon N. Wood simon.wood@r-project.org

References

http://www.maths.bris.ac.uk/~sw15190/