dear R wizards--- I am looking for a reference that explains how to work with formula objects. for example, say, I have a formula which I want to use in an NLS. I want to test what this formula to see if my function was defined correctly. Is there a way to apply a formula to data? For example,
my.formula = (y ~ a+b*x^2) x= 1:10; a=2; b=3; computed.y= apply.a.formula( my.formula, x, a, b ) I know that this has issues, not the least of which is that a formula may not return a y. and that an lm() specification would require me to infer that I have an implicit coefficient vector that is not even specified (i.e., y~x really is y~a+b*x). so, is there a reference to formula objects somewhere? sincerely, /iaw ---- Ivo Welch (ivo.we...@brown.edu, ivo.we...@gmail.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.
