Message-ID: <20061208095255.GA4092@s1x.fischer-zim.local>
Date: 2006-12-08T09:52:55Z
From: wolfram at fischer-zim.ch
Subject: lattice: defining an own function using args for "formula" and "groups"
x.fun <- function( formula, data ) dotplot( formula, data )
x.grp <- function( formula, groups, data ) dotplot( formula, groups, data )
data( barley )
> x.fun( variety ~ yield | site, data=barley )
# no problem
> dotplot( variety ~ yield | site, groups=year, data=barley )
# no problem
> x.grp( variety ~ yield | site, groups=year, data=barley )
object "year" not found # that's my error, so I do:
> x.grp( variety ~ yield | site, groups=barley$year, data=barley )
Error in eval(expr, envir, enclos) : numeric 'envir' arg not of length one
> traceback()
9: eval(substitute(groups), data, environment(formula))
8: bwplot.formula(x = formula, data = c(2, 2, 2, 2, 2, 2, 2, 2, ...
Why it is a problem calling x.grp() and no problem calling x.fun() ?
What could I do to get work x.grp() ?
Thanks - Wolfram