Full_Name: Gabor Grothendieck
Version: R version 1.9.1, 2004-08-03
OS: Windows XP
Submission from: (NULL) (207.35.143.52)
The following gives an error:
> `a(b)` <- 1:4
> `c(d)` <- (1:4)^2
> lm(`a(b)` ~ `c(d)`)
Error in model.matrix.default(mt, mf, contrasts) :
model frame and formula mismatch in model.matrix()
To fix it replace this line in model.matrix.default:
reorder <- match(attr(t, "variables")[-1], names(data))
with these two lines:
strip.backquote <- function(x) gsub("^`(.*)`", "\\1", x)
reorder <- match(strip.backquote(attr(t, "variables"))[-1],
strip.backquote(names(data)))