I tried the following ordered logistic regression in R: mod1 <- polr(altitude~sp + wind_dir + wind_speed + hr, data=altioot) But when I asked The summary of my regression I got the folloing error message:> summary (mod1)Re-fitting to get Hessian Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess, ...) : the initial value of 'vmin' is not finished. I decided to try it in SAS with the following program: PROC LOGISTIC DATA=altioot; CLASS sp wind_dir ; title "mod1"; output out=mod1; MODEL altitude = sp wind_dir wind_speed hr; RUN; And it ran well with an good output. So my question is: Can someone tell me what is the difference between the ordered logistic regression of R and that of SAS? Does anyone have a suggestion to help me run my program in R? Thank you very much, Emilie Berthiaume graduate student Biology Department Sherbrooke University Sherbrooke, Quebec CANADA emilie.berthiaume@USherbrooke.ca [[alternative HTML version deleted]]
Emilie Berthiaume wrote:> I tried the following ordered logistic regression in R: > > mod1 <- polr(altitude~sp + wind_dir + wind_speed + hr, data=altioot)You might also try library(Design) # also requires Hmisc package mod1 <- lrm(....) mod1 summary(mod1) anova(mod1) Frank Harrell> > But when I asked The summary of my regression I got the folloing error message: > > >>summary (mod1) > > > Re-fitting to get Hessian > > Error in optim(start, fmin, gmin, method = "BFGS", hessian = Hess, ...) : > the initial value of 'vmin' is not finished. > > I decided to try it in SAS with the following program: > > PROC LOGISTIC > DATA=altioot; > CLASS sp wind_dir ; > title "mod1"; > output out=mod1; > MODEL altitude = sp wind_dir wind_speed hr; > RUN; > > And it ran well with an good output. So my question is: Can someone tell me what is the difference between the ordered logistic regression of R and that of SAS? Does anyone have a suggestion to help me run my program in R? > > Thank you very much, > > Emilie Berthiaume > graduate student > Biology Department > Sherbrooke University > Sherbrooke, Quebec > CANADA > > emilie.berthiaume at USherbrooke.ca > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html >-- Frank E Harrell Jr Professor and Chair School of Medicine Department of Biostatistics Vanderbilt University