search for: catmod

Hi, we try to do a logistic regression with the function glm. But we notice that this function don't give the same results as the SAS proc catmod (differents estimate given). We try to change the contrast on R system with: > options(contrasts=c(unordered="contr.SAS",ordered="contr.poly")) We also try with brlr and logistf functions. Unfortunately, the estimate aren't still the same. Please could someone help us....

Dear R-experts! In a meta-analysis (metafor) I would like to assess the effect of two categorical covariates (A & B) whereas they both have 4 levels. Is my understanding correct that this would require to dummy-code (0,1) each level of each covariate (A & B)? However I am interested in the main-effects and the interaction of these two covariates and the dummy-coding would only allow to

...enieur en informatique et statistiques et je dois réaliser mon projet de fin d'études sur le logiciel R. En fait, je dois réaliser un scoring sous R puis le meme sous SAS et comparer les resultats. Mon fichier se prete à une regression logistique. J'ai donc utilisé la fonction glm sous R et Catmod sous SAS seumement, je ne parviens pas au meme resultats, les estimateurs different d'une methode a l'autre. Avez vous une idee d'ou peut provenir cette difference? Je vous remercie d'avance Cordialement, --------------------------------- mails ! [[alternative HTML version...

Hello, I am getting some results from my Probit estimation in R that are in the opposite direction of what I hypothesized. In sas, the default is probability that y=0 (instead of 1) so one needs to type the word "descending" to get P(y=1). Is the same true for R? Is the default set to P(0)? Thank you in advance. Nita Umashankar [[alternative HTML version deleted]]