Hello, Still a newbie with R, though I have learned a lot from reading this list. I'm hoping someone can help with this question:
I have two vectors, one for variables, and one for bits. I want to build a string (really a formula) based on the values in my vector of 1s and 0s in bits. If I have a one, I want to include the corresponding entry in the vars vector, otherwise ignore it. Of course the "bits" vector will not stay the same. So for example: vars=c('X.1', 'X.2', 'X.3', 'X.4', 'X.5') bits=c(1, 0, 1, 1, 0) ones=which(bits==1) should yield: "X.1 + X.3 + X.4" where as bits=c(1, 1, 0, 0, 0) would yield "X.1 + X.2" the "which" operator gives me the index values, is there an easy and *efficient* way to build this string so that I can pass it on to glm? I can probably hack some ugly code together to do this, but it won't be efficient, and it won't be elegant :-) Can anyone help? Thanks! ______________________________________________ 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.