On Sat, 29 Jan 2011, Kang Min wrote:
> Thanks Prof Ripley, the condition worked!
> Btw I tried to search ?repl but I don't have documentation for it. Is
> it in a non-basic package?
I meant grepl: the edit messed up (but not on my screen, as sometimes
happens when working remotely). The point is that 'perl=TRUE'
guarantees that [A-J] is interpreted in ASCII order.
>
>
> On Jan 29, 6:54 pm, Prof Brian Ripley <rip... at stats.ox.ac.uk> wrote:
>> The grep comdition is "[A-J]"
>>
>> BTW, why there are lots of unnecessary steps here, including using
>> cbind() and subset():
>>
>> x <- rep(LETTERS[1:20],3)
>> y <- rep(1:3, 20)
>> z <- paste(x,y, sep="")
>> random.data <- rnorm(60)
>> data <- data.frame(z, random.data)
>> data[grepl("[A-J]", z), ]
>>
>> Now (for the paranoid and not needed in this example) in general the
>> effect of "[A-Z]" depends on the locale, so you could write out
>> "[ABCDEFIJK]" or create it by
>>
>> cond <- paste("[", paste(LETTERS[1:10], collapse=""), "]", sep="")
>>
>> Or use repl("[A-J]", z, perl=TRUE).
>>
>>
>>
>> On Sat, 29 Jan 2011, Kang Min wrote:
>>> Hi all,
>>
>>> I would like to subset a dataframe by using part of the level name.
>>
>>> x <- rep(LETTERS[1:20],3)
>>> y <- rep(1:3, 20)
>>> z <- paste(x,y, sep="")
>>> random.data <- rnorm(60)
>>> data <- as.data.frame(cbind(z, random.data))
>>
>>> I need rows that contain the letters A to J, so I tried:
>>
>>> subset(data, grepl(LETTERS[1:10], z)) # got only rows with A
>>> subset(data, z %in% LETTERS[1:10]) # got no rows
>>
>>> I think I'm getting close to the solution but need a little bit of
>>> help here, thanks in advance.
>>
>>> Kang Min
>>
>>> ______________________________________________
>>> R-h... at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>> --
>> Brian D. Ripley, rip... at stats.ox.ac.uk
>> Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
>> University of Oxford, Tel: +44 1865 272861 (self)
>> 1 South Parks Road, +44 1865 272866 (PA)
>> Oxford OX1 3TG, UK Fax: +44 1865 272595
>>
>> ______________________________________________
>> R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at 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.
>
--
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595