Apologizies, I forgot the subject. Btw, I found it stefano Il giorno 01/feb/06, alle ore 18:25, stefano iacus ha scritto:
> Suppose X is a data.frame with n obs and k vars, all variables are > factors. > > tab <- table(X) > > containes a k-dim array > > I would like to get a list from tab. This list is such that, each > element contain the indexes corresponding to the observations which > are in the same cell of this k-dim array. Of course, only for non > empty cell. > > E.g. > >> set.seed(123) >> X <- as.data.frame(matrix(rnorm(5000),100,5)) >> X$V1 <- cut(X$V1, br=5) >> X$V2 <- cut(X$V2, br=5) >> X$V3 <- cut(X$V3, br=5) >> X$V4 <- cut(X$V4, br=5) >> X$V5 <- cut(X$V5, br=5) >> tab <- table(X) >> which(tab>0) -> cells >> length(cells) > [1] 94 > > thus, of course, 94 cells over 5^5 = 3125 are non empty. > I would like a smart way (without reimplementing table/tabulate) to > get the list of length 94 which contains the indexes of the obs in > each cell > Or, viceversa, a vector of length n which tells, observation by > observation, which cell (out of the 3125) the observation is in. > stefano > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
