On Sep 21, 2011, at 10:25 AM, n wrote: > Hello all, > > Suppose in a logistic regression model, the binary outcome is coded as > 0 or 1. > In SAS, the default probability computed is for Y = 0 (smaller of the > two values) . However, in SPSS the probability computed is for Y = 1 > (greater of the two values). > > Which one does R compute, the probability for the smaller or the > greater value? > > I went through the documentation in a hurry but couldn't find a clue. > > Thanks > > Nikhil
>From ?glm in the Details section: For binomial and quasibinomial families the response can also be specified as a factor (when the first level denotes failure and all others success) or as a two-column matrix with the columns giving the numbers of successes and failures. So P(Y = 1) if using 0/1. HTH, Marc Schwartz ______________________________________________ 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.
