Re: [R] plyr and table question
On Fri, Apr 3, 2009 at 4:43 AM, baptiste auguie ba...@exeter.ac.uk wrote: Dear all, I'm puzzled by the following example inspired by a recent question on R-help, cc - textConnection(user_id website time 20 google 0930 21 yahoo 0935 20 facebook 1000 25 facebook 1015 61 google 0940) d - read.table(cc, head=T) ; close(cc) table(d$user_id) # count the occurrences # now I'd like to include these results in the original data.frame, ddply(d, .(website), transform, count = table(user_id)) # why two new columns? Because ddply expects a data frame as output from your aggregation function. When the output isn't a data frame, it calls as.data.frame, which in this case produces a data frame with two columns. Hadley -- http://had.co.nz/ __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] plyr and table question
baptiste auguie-2 wrote: ddply(d, .(website), transform, count = table(user_id)) # why two new columns? Try this to see why: as.data.frame(table(d$user_id)) This works more like you expect: ddply(d, .(website), transform, count = unclass(table(user_id))) - Tom -- View this message in context: http://www.nabble.com/plyr-and-table-question-tp22865174p22868047.html Sent from the R help mailing list archive at Nabble.com. __ 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.
Re: [R] plyr and table question
On Fri, Apr 3, 2009 at 8:43 AM, baptiste auguie ba...@exeter.ac.uk wrote:
That makes sense, so I can do something like,
count - function(x){
as.integer(unclass(table(x)))
}
count(d$user_id)
ddply(d, .(user_id), transform, count = count(user_id))
user_id website time count
1 20 google 930 2
2 20 facebook 1000 2
3 21 yahoo 935 1
4 25 facebook 1015 1
5 61 google 940 1
Have I missed a built-in function to obtain this result?
ddply(d, .(user_id), transform, count = nrow)
?
Hadley
--
http://had.co.nz/
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] plyr and table question
That makes sense, so I can do something like,
count - function(x){
as.integer(unclass(table(x)))
}
count(d$user_id)
ddply(d, .(user_id), transform, count = count(user_id))
user_id website time count
1 20 google 930 2
2 20 facebook 1000 2
3 21yahoo 935 1
4 25 facebook 1015 1
5 61 google 940 1
Have I missed a built-in function to obtain this result?
Thanks,
baptiste
On 3 Apr 2009, at 14:16, hadley wickham wrote:
On Fri, Apr 3, 2009 at 4:43 AM, baptiste auguie ba...@exeter.ac.uk
wrote:
Dear all,
I'm puzzled by the following example inspired by a recent question on
R-help,
cc - textConnection(user_id website time
20google0930
21yahoo0935
20facebook1000
25facebook1015
61google0940)
d - read.table(cc, head=T) ; close(cc)
table(d$user_id) # count the occurrences
# now I'd like to include these results in the original data.frame,
ddply(d, .(website), transform, count = table(user_id)) # why two new
columns?
Because ddply expects a data frame as output from your aggregation
function. When the output isn't a data frame, it calls as.data.frame,
which in this case produces a data frame with two columns.
Hadley
--
http://had.co.nz/
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] plyr and table question
of course!
Thanks,
baptiste
On 3 Apr 2009, at 14:48, hadley wickham wrote:
On Fri, Apr 3, 2009 at 8:43 AM, baptiste auguie ba...@exeter.ac.uk
wrote:
That makes sense, so I can do something like,
count - function(x){
as.integer(unclass(table(x)))
}
count(d$user_id)
ddply(d, .(user_id), transform, count = count(user_id))
user_id website time count
1 20 google 930 2
2 20 facebook 1000 2
3 21yahoo 935 1
4 25 facebook 1015 1
5 61 google 940 1
Have I missed a built-in function to obtain this result?
ddply(d, .(user_id), transform, count = nrow)
?
Hadley
--
http://had.co.nz/
_
Baptiste Auguié
School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK
Phone: +44 1392 264187
http://newton.ex.ac.uk/research/emag
__
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.
