Hello list, Is there any mean to fit models for ordinal response other than multinomial polytomous ("multinom" from nnet ) and cumulative logit ("polr" from MASS)? I am particularly interested in continuation-ratio model and adjacent-category logit model. It is for the sake of epidemiology in wild-living populations! Many thanks, Emmanuelle Fromont ************************************ Emmanuelle Fromont / India UMR CNRS 5558 Universit? Lyon 1 43 Bd du 11 novembre 1918 69622 Villeurbanne Cedex France tel (0)4 72 44 80 18 / poste 48018 fax (0)4 78 89 27 19 ************************************ -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
The lrm function in the Design library in conjunction with the cr.setup function makes this easy. See an extended case study using lrm in my 1998 Statistics in Medicine paper or my book Regression Modeling Strategies. Also see http://hesweb1.med.virginia.edu/biostat/rms and @Article{gui00ord, author = {Guisan, Antoine and Harrell, Frank E.}, title = {Ordinal response regression models in ecology}, journal = {Journal of Vegetation Science}, year = 2000, volume = 11, pages = {617-626}, annote = {teaching;ordinal logistic model} } for more information. -Frank Harrell On Fri, 3 May 2002 09:50:52 +0200 Emmanuelle Fromont <fromont at biomserv.univ-lyon1.fr> wrote:> Hello list, > > Is there any mean to fit models for ordinal response other than multinomial > polytomous ("multinom" from nnet ) and cumulative logit ("polr" from MASS)? > I am particularly interested in continuation-ratio model and > adjacent-category logit model. It is for the sake of epidemiology in > wild-living populations! > > Many thanks, > > Emmanuelle Fromont > > > > > > ************************************ > Emmanuelle Fromont / India > UMR CNRS 5558 > Universit? Lyon 1 > 43 Bd du 11 novembre 1918 > 69622 Villeurbanne Cedex France > tel (0)4 72 44 80 18 / poste 48018 > fax (0)4 78 89 27 19 > ************************************ > > > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- > r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html > Send "info", "help", or "[un]subscribe" > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._-- Frank E Harrell Jr Prof. of Biostatistics & Statistics Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
At 09:50 AM 5/3/2002 +0200, you wrote:>Hello list, > >Is there any mean to fit models for ordinal response other than multinomial >polytomous ("multinom" from nnet ) and cumulative logit ("polr" from MASS)? >I am particularly interested in continuation-ratio model and >adjacent-category logit model. It is for the sake of epidemiology in >wild-living populations!Dear Emmaneulle, Continuation-ratio models are just a collection of binomial (or binary) logit models, each of which can be fit with glm. So, for example, if you have categories A, B, and C, you'd fit a model in which the response is A vs. (B or C), and another in which the response is B vs. C. In the second model, the response if NA for those in category A. The models are independent, so, for example, you can add corresponding log-likelihood ratio statistics and df. I believe that the adjacent-categories logit model is equivalent to the multinomial logit model. To get the coefficients for the log-odds of category i vs. i + 1 [i.e., log(pi_i/pi_{i+1})], subtract the multinomial logit coefficients for category i + 1 (vs. the baseline) from the coefficients for category i. (You should check that this is right -- I might not remember it correctly.) I hope that this helps, John ----------------------------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario, Canada L8S 4M4 email: jfox at mcmaster.ca phone: 905-525-9140x23604 web: www.socsci.mcmaster.ca/jfox ----------------------------------------------------- -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
> > Hello list, > > Is there any mean to fit models for ordinal response other than multinomial > polytomous ("multinom" from nnet ) and cumulative logit ("polr" from MASS)? > I am particularly interested in continuation-ratio model and > adjacent-category logit model. It is for the sake of epidemiology in > wild-living populations!nordr in my gnlm library at www.luc.ac.be/~jlindsey/rcode.html will fit these models, including nonlinear regression. Jim> > Many thanks, > > Emmanuelle Fromont > > > > > > ************************************ > Emmanuelle Fromont / India > UMR CNRS 5558 > Universit? Lyon 1 > 43 Bd du 11 novembre 1918 > 69622 Villeurbanne Cedex France > tel (0)4 72 44 80 18 / poste 48018 > fax (0)4 78 89 27 19 > ************************************ > > > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- > r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html > Send "info", "help", or "[un]subscribe" > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._ >-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._