I have formulae with coefficents that I would like to update. However, I get some strange results. For example, see the following:
For the formula y ~ d+ 3*r+t I want to add a variable p, so > update(y~d+0*r+t, .~.+p) produces y ~ d + t + p - 1 If the coefficient is not 0, but rather, something else - say, 3, I get the following: > update(y~d+3*r+t, .~.+p) Error in terms.formula(tmp, simplify = TRUE) : invalid model formula in ExtractVars > Is there a way to do this, or a different call I should be trying? -Jarrett ______________________________________________ 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.
