Hi r-help-boun...@r-project.org napsal dne 19.01.2011 09:51:43:
> > Hello everyone, > > I have a data set like this: > > > head( fish_transect) > ID_TRANSECT ID_PROJECT DE_ZONE DE_LOCALITY DE_SECTOR MES > 1 42 MB Tarragona Creixell Control I 9 > 2 42 MB Tarragona Creixell Control I 9 > 3 42 MB Tarragona Creixell Control I 9 > 4 42 MB Tarragona Creixell Control I 9 > 5 42 MB Tarragona Creixell Control I 9 > 6 42 MB Tarragona Creixell Control I 9 > ID_SPECIES WEIGHT SIZE N FAMILIA > 1 Spondyliosoma cantharus 15.64 10 1 Sparidae > 2 Symphodus melanocercus 11.21 10 1 Labridae > 3 Diplodus vulgaris 30.20 10 2 Sparidae > 4 Diplodus vulgaris 52.24 12 2 Sparidae > 5 Diplodus sargus 221.41 14 5 Sparidae > 6 Diplodus annularis 3.47 6 1 Sparidae > > The table function of the column FAMILIA gives: <snip> > > I want to add a new column "familia2" where those families with low number > of individuals are listed as "other", that is, for these families > Atherinidae Blenniidae Bothidae Carangidae Centracanthidae > 1 2 11 25 > 4 > Congridae Gadidae Haemulidae Mugilidae > Muraenidae > 21 2 25 10 > 45 > Myliobatidae Scombridae Sphyraenidae Synodontidae > Torpedinidae > 2 1 5 1 > 1 > Trachinidae > 1 > Use levels make new column fish_transect$familia2 <- fish_transect$familia change levels levels(fish_transect$familia2)[which(table(fish_transect$familia2)<46)]<-"other" You can use any threshold number. Regards Petr BTW you need to have familia as factor not as character variable. > I want them in column "familia2" to be named "others" > > I've been trying to do a loop telling R to write "others" when the sum of > FAMILIA was less than 50, but it didn't work because FAMILIA is a factor, > and there isn't a "count" function (or I didn't find it). I also tried other > options like the "match" function, "level" function, etc. I know I can do it > manually typing by myself the names of the 16 families but I want to learn a > way to do where I don't need to type the names. > > Thanks in advance! > > Lucia > > > -- > View this message in context: http://r.789695.n4.nabble.com/count-of-factors- > tp3224791p3224791.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. ______________________________________________ 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.
