Care to tell us why you think you need such an index? I suspect you do not.
Cheers, Bert On Tue, Oct 30, 2012 at 12:21 PM, Meredith, Christy S -FS <csmered...@fs.fed.us> wrote: > Not quite, > I need it like this, a new number for each ordered year in the sequence > within each site, regardless of what the years are, and to retain the RchID > column. > > RchID site year index > 1 A 2002 1 > 2 A 2004 2 > 3 A 2005 3 > 4 B 2003 1 > 5 B 2006 2 > 6 B 2008 3 > 7 C 2002 1 > 8 C 2003 2 > 9 C 2004 3 > > > Thanks so much for you help! > > -----Original Message----- > From: William Dunlap [mailto:wdun...@tibco.com] > Sent: Tuesday, October 30, 2012 1:07 PM > To: Meredith, Christy S -FS; r-help@R-project.org > Subject: RE: [R] help with for loop: new column giving count of observation > for each SITEID > > Is this what you want? > > withinGroupIndex <- function(group, ...) ave(integer(length(group)), > group, ..., FUN=seq_along) > > site <- c("A","A","C","D","C","A","B") > > data.frame(site, index=withinGroupIndex(site)) > site index > 1 A 1 > 2 A 2 > 3 C 1 > 4 D 1 > 5 C 2 > 6 A 3 > 7 B 1 > > You can add more arguments if the groups depend on more than one value: > > year <- rep(c(1985, 2012), c(4,3)) > > data.frame(site, year, index=withinGroupIndex(site, year)) > site year index > 1 A 1985 1 > 2 A 1985 2 > 3 C 1985 1 > 4 D 1985 1 > 5 C 2012 1 > 6 A 2012 1 > 7 B 2012 1 > > Bill Dunlap > Spotfire, TIBCO Software > wdunlap tibco.com > > >> -----Original Message----- >> From: r-help-boun...@r-project.org >> [mailto:r-help-boun...@r-project.org] On Behalf Of Meredith, Christy S >> -FS >> Sent: Tuesday, October 30, 2012 11:17 AM >> To: r-help@R-project.org >> Subject: [R] help with for loop: new column giving count of >> observation for each SITEID >> >> >> Hello, >> I think this is easy, but I can't seem to find a good way to do this >> in the R help. I have a list of sites, with multiple years of data for >> each site id. I want to create a new column that gives a number >> describing whether it is the 1st year ("1" ) the data was collected >> for the site, the second year ("2"), etc. I have different years for >> each siteid, but I don't care which year it was collected, just the order >> that it is in for that siteid. This is what I have so far, but it doesn't >> do the analysis separately for each SiteID. >> >> indexi<-indexg[order(indexg$SiteID,indexg$Yr),] >> >> obs=0 >> indexi=na.omit(indexi) >> for(i in 1:length(indexi$SiteID)){ >> obs=obs+1 >> indexi$obs[i]=obs >> } >> >> >> Thanks for any help you can give. >> >> Christy Meredith >> USDA Forest Service >> Rocky Mountain Research Station >> PIBO Monitoring >> Data Analyst >> Voice: 435-755-3573 >> Fax: 435-755-3563 >> >> >> >> >> >> This electronic message contains information generated by the USDA >> solely for the intended recipients. Any unauthorized interception of >> this message or the use or disclosure of the information it contains >> may violate the law and subject the violator to civil or criminal >> penalties. If you believe you have received this message in error, please >> notify the sender and delete the email immediately. >> >> [[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. > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.
