Thanks David for your fast reply, but now I realized tat "string" is of type:
> class(string) [1] "jobjRef" attr(,"package") [1] "rJava" so I get an error when i try with gsub or sub: > sub("^.+\\t(\\d+)\\n.+$", "\\1", string) Error in as.character.default(x) : no method for coercing this S4 class to a vector I think that there should be trivial solution, but... Any further idea? Regards, Andrej On Jun 16, 6:47 pm, David Winsemius <dwinsem...@comcast.net> wrote: > On Jun 16, 2010, at 12:04 PM, Andrej wrote: > > > Dear all, > > > I'm trying to filter out the "number of leaves" (it should be 1 in the > > example below) from the following string: > > >> string > > [1] "Java-Object{J48 pruned tree\n------------------\n: 0 (15.0/3.0)\n > > \nNumber of Leaves : \t1\n\nSize of the tree : \t1\n}" > > > Any idea how to do that as simple as possible? Thanks in advance for > > any advice. > > ?sub # or ?gsub if you need more than one pattern matched (they are > on the same page). > > This should find the first occurrence of digits following a tab > terminated by a line feed and then return only the digits: > > string <- "Java-Object{J48 pruned tree\n------------------\n: 0 > (15.0/3.0)\n \nNumber of Leaves : \t1\n\nSize of the tree : \t1\n}" > sub("^.+\\t(\\d+)\\n.+$", "\\1", string) > [1] "1" > > The parens within the search pattern are matched to "\\1". Need to > double backslashed within patterns. > > > > > Regards, Andrej > > -- > > David Winsemius, MD > West Hartford, CT > > ______________________________________________ > r-h...@r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://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.