[R] order in lapply

Sundar Dorai-Raj sundar.dorai-raj at pdf.com
Wed Jul 2 20:46:05 CEST 2003



Ernesto Jardim wrote:
> Hi
> 
> When using "split" is it possible to keep then same ordering of the
> factor on the output list ?
> 
> Thanks
> 
> EJ
> 

There may be an easier way to do this but I would make the split 
variable ordered before calling split. As in:

 > d = data.frame(a = 1:4, b = c("d", "c"))
 > sapply(d, data.class)
         a         b
"numeric"  "factor"
 > split(d$a, d$b)
$c
[1] 2 4

$d
[1] 1 3

 > d$b = ordered(d$b, c("d", "c"))
 > sapply(d, data.class)
         a         b
"numeric" "ordered"
 > split(d$a, d$b)
$d
[1] 1 3

$c
[1] 2 4

 >

Regards,
Sundar




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