@Josh Thanks! That's exactly what I need. @ Marc. I want to do this manually because I want to do many things with the data beyond R's built in functions.
-- Noah Silverman UCLA Department of Statistics 8117 Math Sciences Building Los Angeles, CA 90095 On Aug 23, 2011, at 10:43 AM, Joshua Wiley wrote: > On Tue, Aug 23, 2011 at 10:34 AM, Noah Silverman <noahsilver...@ucla.edu> > wrote: >> Hi, >> >> Looking at a large data set with many factors. >> >> I would like to expand each factor variable into multiple new variables for >> each level. (0,1) coding. >> >> My first though was just to code a big nasty loop, to take each level and >> cbind a column onto my data set. But, that seems painful. There must be a >> better way. >> >> Is there an "easy" way to do this in R? > > Sure, just use model matrix, e.g.: > > model.matrix(~ -1 + factor(cyl), data = mtcars) > > Cheers, > > Josh > >> >> (Note, I don't want to internally represent the levels in the data set, but >> physically have new columns for each level with a binary indicator.) >> >> Thanks! >> >> -- >> Noah Silverman >> UCLA Department of Statistics >> 8117 Math Sciences Building >> Los Angeles, CA 90095 >> >> ______________________________________________ >> 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. >> > > > > -- > Joshua Wiley > Ph.D. Student, Health Psychology > Programmer Analyst II, ATS Statistical Consulting Group > University of California, Los Angeles > https://joshuawiley.com/ ______________________________________________ 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.