Frank, I certainly can't speak for Emmanuel. I don't know his reasons.
The reason I've posted this question is the fact that (as far as I understood), ordinal regression is based on logistic regression (or probit), and logistic regression expects a formula like dichotomous ~ ratio1 + ratio2 + ... + ration. However, most examples I've found in Design, MASS and VGAM test models like ordinal ~ categorical1 + categorical2 + ... + categoricaln. I wonder if it is just coincidence or I have just found the wrong functions. Best, Iuri. On Mon, Nov 9, 2009 at 11:43 AM, Frank E Harrell Jr <f.harr...@vanderbilt.edu> wrote: > Emmanuel Charpentier wrote: >> >> Le dimanche 08 novembre 2009 à 19:05 -0600, Frank E Harrell Jr a écrit : >>> >>> Emmanuel Charpentier wrote: >>>> >>>> Le dimanche 08 novembre 2009 à 17:07 -0200, Iuri Gavronski a écrit : >>>>> >>>>> Hi, >>>>> >>>>> I would like to fit Logit models for ordered data, such as those >>>>> suggested by Greene (2003), p. 736. >>>>> >>>>> Does anyone suggests any package in R for that? >>>> >>>> look up the polr function in package MASS (and read the relevant pages >>>> in V&R4 and some quoted references...) or the slightly more >>>> sophisticated (larger range of models) lrm function in F. Harrell's >>>> Design (now rms) packge (but be aware that Design is a huge beast witch >>>> carries its own "computing universe", based on (strong) Harrell's view >>>> of what a regression analysis should be : reading his book is, IMHO, >>>> necessary to understand his choices and agree (or disgree) with them). >>>> >>>> If you have a multilevel model (a. k. a. one "random effect" grouping), >>>> the "repolr" packge aims at that, but I've been unable to use it >>>> recently (numerical exceptions). >>>> >>>>> By the way, my dependent variable is ordinal and my independent >>>>> variables are ratio/intervalar. >>>> >>>> Numeric ? Then maybe some recoding/transformation is in order ... in >>>> which case Design/rms might or might not be useful. >>> >>> I'm not clear on what recoding or transformation is needed for an ordinal >>> dependent variable and ratio/interval independent variables, nor why >>> rms/Design would not be useful. >> >> I was thinking about transformations/recoding of the *independent* >> variables... >> Emmanuel Charpentier > > I realize that; still unclear. > Frank > > -- > Frank E Harrell Jr Professor and Chair School of Medicine > Department of Biostatistics Vanderbilt University > > ______________________________________________ > 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. > ______________________________________________ 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.