this is good, but it doesn't solve my main problem (which I unfortunately din't post - very sorry ) I would like to filter may data , for example by:
dat.sub<-dat[dat$age>10 & dat$NoCaps>2,] So I need a column where the number of Captures is repeated for all rows of each captured animal. (or is there a better way to get a subset?) thanks. Dimitris Rizopoulos-4 wrote: > > in this case you can use ave(), e.g., say 'dat' is the name of your data > frame, then try this: > > dat$NoCaps <- ave(dat$Id, dat$Id, FUN = length) > dat > > > I hope it helps. > > Best, > Dimitris > > > clion wrote: >> Hi there. >> I collectad data of several animals (Id) that were caught and measured at >> several occasions. >> The dataframe looks like this: >> Grouped Data: mass ~ age | Id >> Id age mass >> 1 1 5.4 >> 1 3 6.2 >> 1 15 10.0 >> 2 3 8.1 >> 2 10 12.8 >> 3 2 5.9 >> 3 10 7.1 >> 3 15 15.4 >> 3 17 16.2 >> >> Now, I would like to add a column that shows the number of captures per >> Animal (so it'll look like this:) >> Id .... NoCaps >> 1 .... 3 >> 1 .... 3 >> 1 .... 3 >> 2 .... 2 >> 2 .... 2 >> 3 .... 4 >> 3 .... 4 >> .... >> >> I understand that with >> tapply(Id,Id, length) >> I can find out how many times each animal was caught, but how do I get >> this >> information into an extra column? I'm sure, this is an easy question, but >> I'm lost, where to find the answer, or especially where to look it up. if >> this is not a new question, please give me the key words to look for >> it... >> >> thanks in advance >> >> >> >> >> >> > > -- > Dimitris Rizopoulos > Assistant Professor > Department of Biostatistics > Erasmus Medical Center > > Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands > Tel: +31/(0)10/7043478 > Fax: +31/(0)10/7043014 > > ______________________________________________ > 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. > > :wistle::wistle::rules::rules::rules: -- View this message in context: http://www.nabble.com/length-of-object-in-repeated-measures-tp21911978p21912355.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.
