Johannes, You can minimize an model expression by just putting the ~ on the left and everything else on the righthand side, but I don't think that this is really what you want. In the NLS expression this would ignore the jacobian of the transformation from errors to response, and in nlrq there is the same problem, however you can adjust for the jacobian by rescaling by the geometric mean of the response. I hope that this helps.
Roger url: www.econ.uiuc.edu/~roger/my.html Roger Koenker email [EMAIL PROTECTED] Department of Economics vox: 217-333-4558 University of Illinois fax: 217-244-6678 Champaign, IL 61820 On Thu, 20 Nov 2003, Johannes Ludsteck wrote: > Dear Mr. Koenker, > sorry for bothering you. I have a probably trivial problem with > your nlrq procedure. > > I would like to estimate the simple box-cox tranformed model > > nlrq(I(y^t-1)/t) ~ I(a+b*x), data=df, start = c(t=1,a=0,b=0)) > > R returns with the error message > Error in unique(c("AsIs", oldClass(x))) : Object "t" not found > > Is nlrq not able to handle transformations of the left hand side > variable or have I maked a mistake? > > Thanks for every help and best regards, > Johannes Ludsteck > <><><><><><><><><><><><> > Johannes Ludsteck > Economics Department > University of Regensburg > Universitaetsstrasse 31 > 93053 Regensburg > Phone +49/0941/943-2741 > > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help