Patrick,
On Dec 28, 2011, at 12:07 AM, Patrick Leyshock wrote:
> I have an external pointer object that I'd like to pass from my R code to
> some C code. Per Section 5.13 of "Writing R Extensions", I've noted that
> "external pointers should only be used as part of an object with normal
> semant
Hi all,
There seems to be rather a large speed disparity in subsetting when
working with a whole data frame vs. working with just columns
individually:
df <- as.data.frame(replicate(10, runif(1e5)))
ord <- order(df[[1]])
system.time(df[ord, ])
# user system elapsed
# 0.043 0.007 0.059
sy
Hadley,
there was a whole discussion about subsetting and subassigning data frames (and
general efficiency issues) some time ago (I can't find it in a hurry but others
might) -- just look at the `[.data.frame` code to see why it's so slow. It
would need to be pushed into C code to allow certain
On Wed, Dec 28, 2011 at 8:14 AM, Simon Urbanek
wrote:
> Hadley,
>
> there was a whole discussion about subsetting and subassigning data frames
> (and general efficiency issues) some time ago (I can't find it in a hurry but
> others might)
Yep, a rather lengthy discussion at that
http://r.789695
Ah, thanks for the pointers!
Hadley
On Wed, Dec 28, 2011 at 10:14 AM, Simon Urbanek
wrote:
> Hadley,
>
> there was a whole discussion about subsetting and subassigning data frames
> (and general efficiency issues) some time ago (I can't find it in a hurry but
> others might) -- just look at the
