Thanks, That gives me exactly what I'm looking for.
Two quick questions: 1) What would be the fastest way to do this if I have other continuous data as well. For example, I have a data frame with 10 variable and want to discretize one of them using this method. (Say, column 6 for example.) I thought something like this would work, but it gives me an error: new.data <- rbind(data[,1:5], model.matrix(~0+data[,6]), data[,7:10]) Error in rbind(deparse.level, ...) : numbers of columns of arguments do not match 2) What exactly is it doing? It appears as if it is a formula similar to lm, but not actually doing any regression? Thanks again! -N On 5/15/10 11:17 AM, Thomas Stewart wrote: > Maybe this? > > group <- factor(c("A", "B","B","C","C","C")) > model.matrix(~0+group) > > -tgs > > On Sat, May 15, 2010 at 2:02 PM, Noah Silverman > <n...@smartmediacorp.com <mailto:n...@smartmediacorp.com>> wrote: > > Hi, > > I'm looking for an easy way to discretize factors in R > > I've noticed that the lm function does this automatically with a nice > result. > > If I have > > group <- c("A", "B","B","C","C","C") > > and run: > > lm(result ~ x1 + group) > > The lm function has split the group into separate binary variables > {0,1} > before performing the regression. I now have: > groupA > groupB > groupC > > Some of the other models that I want to try won't accept factors, so > they need to be discretized this way. > > Is there a command in R for this, or some easy shortcut? (I tried > digging into the lm code, but couldn't find where this is being done.) > > Thanks! > > -N > > ______________________________________________ > R-help@r-project.org <mailto: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. > > [[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.