if(.R.) units <- function(x,...)  UseMethod("units")

"units<-"  <- function(x, value) {
    attr(x, "units") <- value
    x
    }

units.default <- function(x, none='', ...)  {
	lab <- attr(x, "units")
	if(is.null(lab)) lab <- attr(attr(x,'tspar'),'units')
	if(is.null(lab)) lab <- none
	lab
	}
