> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of Noah Silverman > Sent: Saturday, May 15, 2010 11:03 AM > To: r-help@r-project.org > Subject: [R] Discretize factors? > > 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 >
Noah, You might try something like model.matrix(~ group -1) Hope this is helpful, Dan Daniel Nordlund Bothell, WA USA ______________________________________________ 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.
