Hi Jim Thanks for reply but this is not working. I think I am missing something over here.
1> x <- cbind(c(1,2,2,2,3,4), c('a','b', 'c','d','e','f')) 1> colnames(x) = c('param', 'case1') 1> x = as.data.frame(x) 1> x param case1 1 1 a 2 2 b 3 2 c 4 2 d 5 3 e 6 4 f 1> x[ 1+ , list(case1 = paste(x$case1, collapse = ',')) 1+ , by = x$param 1+ ] Error in `[.data.frame`(x, , list(case1 = paste(x$case1, collapse = ",")), : unused argument(s) (by = x$param) Hi David. Thanks a lot for your help. 1> aggregate(x$case1, x['param'], FUN = paste, collapse=",") param x 1 1 a 2 2 b,c,d 3 3 e 4 4 f 1> Thanks again M On Wed, Dec 21, 2011 at 11:56 AM, David Winsemius <dwinsem...@comcast.net>wrote: > > On Dec 21, 2011, at 11:31 AM, jim holtman wrote: > > Here is an example using 'data.table'" >> >> x <- read.table(text = "param case1 >>> >> + 1 a >> + 2 b >> + 2 c >> + 2 d >> + 3 e >> + 4 f", header = TRUE, as.is = TRUE) >> > > And the aggregate version: > > > aggregate(x$case1, x["param"], FUN=paste, collapse=",") > param x > 1 1 a > 2 2 b,c,d > 3 3 e > 4 4 f > > ( Generally one uses the "[[" function for extraction, but using "[" > returns a list which is what aggregate is designed to process as its second > argument, whereas you would get an error with either of these: > > aggregate(x$case1, x$param, FUN=paste, collapse=",") > aggregate(x$case1, x[["param"]], FUN=paste, collapse=",") > > ) > > require(data.table) >>> x <- data.table(x) >>> x[ >>> >> + , list( case1 = paste(case1, collapse = ',')) >> + , by = param >> + ] >> param case1 >> [1,] 1 a >> [2,] 2 b,c,d >> [3,] 3 e >> [4,] 4 f >> >>> >>> >> >> On Wed, Dec 21, 2011 at 11:26 AM, Mary Kindall <mary.kind...@gmail.com> >> wrote: >> >>> Hi >>> I have a data frame with values in following format. >>> >>> >>> param case1 >>> 1 a >>> 2 b >>> 2 c >>> 2 d >>> 3 e >>> 4 f >>> >>> >>> how to use aggregate so that it I only one row for each 'param' value. >>> >>> the output for the above input should be >>> >>> param case1 >>> 1 a >>> 2 b,c,d >>> 3 e >>> 4 f >>> >>> Thanks >>> M >>> >>> >>> >>> -- >>> ------------- >>> Mary Kindall >>> Yorktown Heights, NY >>> USA >>> >>> [[alternative HTML version deleted]] >>> >>> ______________________________**________________ >>> R-help@r-project.org mailing list >>> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >>> PLEASE do read the posting guide http://www.R-project.org/** >>> posting-guide.html <http://www.R-project.org/posting-guide.html> >>> and provide commented, minimal, self-contained, reproducible code. >>> >> >> >> >> -- >> Jim Holtman >> Data Munger Guru >> >> What is the problem that you are trying to solve? >> Tell me what you want to do, not how you want to do it. >> >> ______________________________**________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> >> PLEASE do read the posting guide http://www.R-project.org/** >> posting-guide.html <http://www.R-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > David Winsemius, MD > West Hartford, CT > > -- ------------- Mary Kindall Yorktown Heights, NY USA [[alternative HTML version deleted]] ______________________________________________ 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.