Hi,
Given factors x and y, c(x,y) does not seem to return a useful result :
> x
[1] a b c d e
Levels: a b c d e
> y
[1] d e f g h
Levels: d e f g h
> c(x,y)
[1] 1 2 3 4 5 1 2 3 4 5
>
Is there a case for a new method c.factor as follows? Does something
similar exist already? Is there a better way to write the function?
> c.factor = function(x,y)
{
newlevels = union(levels(x),levels(y))
m = match(levels(y), newlevels)
ans = c(unclass(x),m[unclass(y)])
levels(ans) = newlevels
class(ans) = "factor"
ans
}
> c(x,y)
[1] a b c d e d e f g h
Levels: a b c d e f g h
> as.integer(c(x,y))
[1] 1 2 3 4 5 4 5 6 7 8
>
Regards,
Matthew
> version
_
platform x86_64-unknown-linux-gnu
arch x86_64
os linux-gnu
system x86_64, linux-gnu
status
major 2
minor 4.0
year 2006
month 10
day 03
svn rev 39566
language R
version.string R version 2.4.0 (2006-10-03)
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