Extend a Formula to all of it's Terms — extend.x.formula • mvabund

extend a compact formula to all of it's terms as they are interpreted

Usage

extend.x.formula(formula, extend.term=TRUE, return.interaction=TRUE)

Arguments

formula: a model formula.
extend.term: logical. If TRUE terms that refer to multiple variables are split into it's multiple terms.
return.interaction: logical. Whether a list containing the new formula and a vector containing logical values with information about interactions should be returned or only the new formula.

Value

If return.interaction is TRUE a list containing the components:

formula: the new formula.
is.interaction: logical, vector giving information whether the corresponding formula term is an interaction or not.

Author

Ulrike Naumann and David Warton <David.Warton@unsw.edu.au>.

See also

mvformula, formulaUnimva, plot.mvformula, best.r.sq.

Examples

data(spider)
spiddat <- mvabund(spider$abund)
X <- spider$x

foo <- mvformula(spiddat~ X[,1]*X[,2]+log(X[,3]))
#> Error in eval(terms(x)[[2]]): object 'spiddat' not found
extend.x.formula(foo)
#> Error in terms(formula): object 'foo' not found