Ah...OK. I misunderstood then. I thought that you wanted the number of runs of 1's in each column.
This is actually easier, _if_ there is not an overlap of 1's from the end of one column to the start of the next column: res <- rle(as.vector(prova)) > res Run Length Encoding lengths: int [1:11] 2 2 2 2 3 3 5 4 2 1 ... values : int [1:11] 3 1 3 1 3 1 3 1 3 1 ... > table(res$lengths[res$values == 1]) 1 2 3 4 1 2 1 1 HTH, Marc On Thu, 2007-11-15 at 17:18 +0100, A M Lavezzi wrote: > Dear Marc > thank you so much! > > One thing: writing xx=[1,2,1,1] is not a typo: I > read it as the count of runs of different length starting from 1. > > In "prova" I have 1 run of length one, 2 runs of > length two, 1 run of length three and 1 run of length four. > > Can I abuse of your time and ask how to do this? > > Thanks again > Mario > > At 16.48 15/11/2007, you wrote: > > >On Thu, 2007-11-15 at 15:51 +0100, A M Lavezzi wrote: > > > Hello > > > > > > I have this problem. I have a large matrix of this sort: > > > > > > > prova > > > [,1] [,2] [,3] [,4] > > > [1,] 3 3 3 3 > > > [2,] 3 3 3 1 > > > [3,] 1 3 3 3 > > > [4,] 1 1 1 3 > > > [5,] 3 1 1 3 > > > [6,] 3 1 1 3 > > > [7,] 1 3 1 3 > > > [8,] 1 3 3 3 > > > > > > What I want to do is to count the number of > > > sequences of ones and stack the results in a > > > vector, which I will subsequently use to build an istogram (or a density) > > > > > > I mean: in the matrix "prova" I have two > > > sequences of length two in column 1, one sequence > > > of length three in column 2, one sequence of > > > length four in column 3 and one sequence of > > > length one in column 4. (I know I can actually > > > turn the matrix into a vector by using rep(prova)) > > > > > > I would like to get to a vector such as : xx = [1,2,1,1] > > > >I presume a typo above and that it should be: > > > > xx = [2,1,1,1] > > > >? > > > >If so: > > > > > unlist(lapply(apply(prova, 2, rle), > > function(x) length(x$lengths[x$values == 1]))) > >[1] 2 1 1 1 > > > > > >See ?rle to get the basics of identifying runs of values. > > > >HTH, > > > >Marc Schwartz > > =============================== > Andrea Mario Lavezzi > Dipartimento di Studi su Politica Diritto e Società > Piazza Bologni 8 > 90134 Palermo > tel. ++39 091 6625600 > fax ++39 091 6112023 > skype: lavezzimario > email: [EMAIL PROTECTED] > web: http://www.unipa.it/~lavezzi > =============================== > ______________________________________________ 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.
