R/variable2term.R

In flexrsurv: Flexible Relative Survival Analysis

variable2term <- function(whichvars, Terms){
	# get the index of the all the terms involving each whichvars in the labels.term
	if(is.null(whichvars)){
		return(NULL)
	}
	else {
		return((1:length(attr(Terms, "term.labels")))[apply(attr(Terms, "factors")[whichvars, , drop=FALSE], MARGIN=2, FUN=sum) >0])
	}
}