Hi, I have a dataset that I am trying to analyze and plot as an ordered logistic regression (y = ordinal categories 1-3, x = continuous variable with values 3-9).
First is a problem with cdplot: Produces a beautiful plot, with the "right" trend, but my independent factor values are transformed. The factor has values from 3-9, but the plot produces an x-axis with values from 20-140. When I force the xlim to be 3-9, it produces a plot without the trend, which can't be correct. Second is a problem with polr: The output of the summary command of the model built with polr includes t values for lots (if not all) of my independent factor values, but does not produce a summary of the fit of the model or of the overall fit of the factor. Also, intercepts are different from those produced with a logistic fit in JMP... Code below, any help much appreciated. Thanks Beth LogAntDensityFactor<-as.factor(LogAntDensity) ###order ordinal variable HammerCatOrd<-ordered(HammerCat) ###set ordered ordinal dependent variable as factor HammerCatOrdFactor<-as.factor(HammerCatOrd) ###density plot with three levels cdplot(HammerCatOrdFactor~LogAntDensityFactor,xlab="Log(Ant Density)",ylab="Latency of response to disturbance (1-3)") require(MASS) logordered<-polr(HammerCatOrdFactor~LogAntDensityFactor,Hess=TRUE) summary(logordered,digits=3) [[alternative HTML version deleted]] ______________________________________________ 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.