R/update.compareGroups.R

In compareGroups: Descriptive Analysis by Groups

update.compareGroups<-
function (object, formula., ..., evaluate = TRUE) 
{
    if(!inherits(object, "compareGroups"))
        stop("argument 'object' must be of class 'compareGroups'")
    
    if(inherits(object, "compareGroups.subset"))
        stop("Update process might not work properly (different variables selected) since 'obj' has been subset previously")
    
    if(inherits(object, "rbind.compareGroups"))
        stop("Update process does not work for rbind.compareGroups objects")

    call <- attr(object,"call")$call
    if (is.null(call)) 
        stop("need an object with call component")
    
    extras <- match.call(expand.dots = FALSE)$...
    
    if (!missing(formula.)){
      if (inherits(formula., "formula")){ 
        if (inherits(eval(call$formula), "formula")){
          call$formula <- update.formula2(call$formula, formula.)
        }else {
          call$data <- call$formula
          call$formula <- formula.
        }
      } else {
        call$formula <- formula.
      }
    }
    if (length(extras)) {
      existing <- !is.na(match(names(extras), names(call)))
      for (a in names(extras)[existing]) call[[a]] <- extras[[a]]
      if (any(!existing)) {
        call <- c(as.list(call), extras[!existing])
        call <- as.call(call)
      }
    }
    if (evaluate)
      eval(call, parent.frame())
    else 
      call
}