interpret.addreg.smooth {addreg}

Interpret an addreg.smooth Formula

Description

This is an internal function of package addreg. It is a service routine for addreg.smooth which interprets the smooth parts of the model formula and returns modified formulas to be used in the fitting functions.

Not normally called directly.

Usage

interpret.addreg.smooth(formula)

Arguments

formula

A formula as supplied to addreg.smooth, which includes at least one B or Iso term.

Value

A list with components:

full.formula

a formula object which is the same as the formula supplied, but with additional arguments removed from the smooth terms. E.g. B(x, knot.range = 0:2) would appear as B(x) in this formula.

fake.formula

a formula object which is the same as the formula supplied, but with smooth terms replaced by their covariates alone. E.g. B(x, knot.range = 0:2) would appear as x in this formula. Used to construct the model matrix.

smooth.spec

a named list containing the results of evaluating the smooth terms. See B and Iso for details.

smooth.ind

a vector containing the indices of the smooth components in the formula.

terms

the result of running terms.formula(formula, specials = c("B", "Iso")).

Author(s)

Mark W. Donoghoe [e-mail]

See Also

addreg.smooth

Examples

# Specify a smooth model with knot.range
res <- interpret.addreg.smooth(y ~ B(x, knot.range = 0:2) + x2)
# The knot.range is removed from the full.formula...
print(res$full.formula)
# ...but is stored in the $smooth.spec component of the result:
print(res$smooth.spec$x$knot.range)