While browsing some code I discovered a call to lm that used a formula y ~ X - 1, where X was a matrix.
Looking through the documentation of formula, lm, model.matrix and maybe some others I couldn't find this useage (R 2.10.1). Is it anything I can count on in future versions? Is there documentation I've overlooked? For the curious: model.frame on the above equation returns a data.frame with 2 columns. The second "column" is the whole X matrix. model.matrix on that object returns the expected matrix, with the transition from the odd model.frame to the regular matrix happening in an .Internal call. Thanks. Ross P.S. I would appreciate cc's, since mail problems are preventing me from seeing list mail. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
