On 08/17/2011 11:51 AM, Marius Hofert wrote:
> Dear all,
>
> thanks a lot for the quick help.
> Below is what I built with the hint of Nick.
>
> Cheers,
>
> Marius
>
>
> library(plyr)
>
> set.seed(1)
> (df <- data.frame(Group=rep(c("Group1","Group2","Group3"), each=10),
> Value=c(rexp(10, 1), rexp(10, 4), rexp(10,
> 10)))[sample(1:30,30),])
> edf <- function(x) ecdf(x)(x)
>
> ddply(df, .(Group), function(df.) cbind(df., edf=edf(df.$Value)))
Hadley's code is much shorter, I would use that syntax.
cheers,
Paul
>
> On 2011-08-17, at 13:38 , Hadley Wickham wrote:
>
>>> The following example does what you want using ddply:
>>>
>>> library(plyr)
>>> edfPerGroup = ddply(df, .(Group), summarise, edf = edf(Value), Value =
>>> Value)
>> Or slightly more succinctly:
>>
>> ddply(df, .(Group), mutate, edf = edf(Value))
>>
>> Hadley
>>
>> --
>> Assistant Professor / Dobelman Family Junior Chair
>> Department of Statistics / Rice University
>> http://had.co.nz/
--
Paul Hiemstra, Ph.D.
Global Climate Division
Royal Netherlands Meteorological Institute (KNMI)
Wilhelminalaan 10 | 3732 GK | De Bilt | Kamer B 3.39
P.O. Box 201 | 3730 AE | De Bilt
tel: +31 30 2206 494
http://intamap.geo.uu.nl/~paul
http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
