Hi Carlos, how about this step first:

rownames(mydata)<-gsub("361a","00361a",rownames(mydata)) rownames(mydata)<-gsub("456a","00456a",rownames(mydata)) good luck milton On Thu, Aug 27, 2009 at 12:27 PM, Carlos Gonzalo Merino Mendez < carlosgmer...@yahoo.com> wrote: > Hello everyone, I would appreciate any help with the following. > > My dataset is a list containing matrices. So if you type e.g. > > data[[1]] > > you get something like: > > [,1] [,2] > 361a A T > 456b A G > 72145a T G > ........ > > As you can see my rows have names which are character strings containing > numbers and letters. I want something similar to a histogram, per column. > i.e. I want to know how many times I have a single repeat character in a > column and how many times I have a twice repeated character and so on. Maybe > there is an easy way to do this, but I wrote my own code which works > perfectly, so don't bother to correct it unless extremely necessary. I write > down the code so you know exactly what I'm trying to do: > > table <- vector() > > for (i in (1:length(data))){ > > for (j in (1:length(data[[i]][1,]))){ > > t <- table(data[[i]][,j]) > > table <- c(table, t) > }} > > ncount <- table[names(table) != "-"] #this line is necessary to eliminate > "-" characters which should not be included in the analysis > > sfs <- table (ncount) > > And with this code I get something like: > > 1 2 3 4 5 6 7 8 9 10 .... > > 542 125 98 49 47 41 26 31 22 18 .... > > which is what I'm looking for. > > > Now comes THE problem: > > As I said before my rows have names. Each name is unique. I want to apply > my analysis to a subset of rows en each matrix, namely all rows whose names > start with 3, all that start with 4, all that start with 721. In most cases > only the first character is important, but since I have names of different > length, in some cases I need the first three characters to differentiate the > groups. I want to integrate this into the loop so that I get a vector (such > as the one called "table" in my code) for each subset analyzed. > > I tried using the subset function, but I couldn't figure out how to use it, > because it's intended to use row values to define the subset, not row names. > > I hope someone can help me out, but please bear in mind I am really new at > R and most commands and parameters are really unfamiliar to me. > > Thanks. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ 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.