[R] expand.grid and the first level of a factor
Giovanni Marchetti
gmm at ds.unifi.it
Sat May 3 14:53:23 CEST 2003
I do not understand this behaviour of expand.grid:
> expand.grid(x = c("b", "a"), y = c(1, 2))$x
[1] b a b a
Levels: b a
> expand.grid(x = c("b", "a"))$x
[1] b a
Levels: a b
Why the first level of the factor x depends on the number
of arguments of expand.grid? Apparently, I can set
the order of the levels only when the number of
arguments in > 1. In the second example, the order
is lexicographic.
-- Giovanni
--
< Giovanni M. Marchetti >
Dipartimento di Statistica, Univ. di Firenze Phone: +39 055 4237 204
viale Morgagni, 59 Fax: +39 055 4223 560
I 50134 Firenze, Italy email: gmm at ds.unifi.it
More information about the R-help
mailing list