On 1 Mar 2007 at 12:17, Aimin Yan wrote:
Date sent: Thu, 01 Mar 2007 12:17:09 -0600 To: [email protected] From: Aimin Yan <[EMAIL PROTECTED]> Subject: [R] number of levels for a factor > I have temp list which have 19 data.frame > I want to get number of levels for pr in the first dat.frame > I do this like this: > temp[[1]]$pr just has "1A24" > after I do nlevels(temp[[1]]$pr) > I expect to get 1, but I get 19 > > anyone know why? Hi help page for [.factor tells you that using subsetting results in A factor with the same set of levels as x unless drop=TRUE. I presume your list resulted from some splitting operation and that original set of levels was preserved. HTH Petr > > > tail(temp[[1]]$pr) > [1] 1A24 1A24 1A24 1A24 1A24 1A24 > 19 Levels: 1A24 1A57 1A5J 1A6X 1AB7 1AF8 1AFI 1AGG 1AH9 1AHL 1AJ3 1AJW > ... 1AZK > > nlevels(temp[[1]]$pr) > [1] 19 > > Aimin > > ______________________________________________ > [email protected] 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. Petr Pikal [EMAIL PROTECTED] ______________________________________________ [email protected] 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.
