Thanks Frank, Two quick questions:
1) I see you calculating datadist, but then not using it in the subsequent entries. Is that for a different application. 2) I'm less concerned with plotting than the values that were plotted. As mentioned in my original message, The line plotted from the fitted logistic looked great. I want those values. Perhaps all I need is the "lrm" line of your example? 3) Your Design library rocks. Thank you so much for making it available to the R community!! -N On 8/21/09 3:00 PM, Frank E Harrell Jr wrote: > A parametric version is: > > require(Design) > dd <- datadist(predprob); options(datadist='dd') > f <- lrm(event ~ rcs(qlogis(predprob), 3)) > plot(f, predprob=NA, fun=plogis) > > Frank > > > Noah Silverman wrote: >> Hello, >> >> Frank was nice enough to point me to the val.prob function of the >> Design library. >> >> It creates a beautiful graph that really helps me visualize how well >> my model is predicting probabilities. >> >> By default, there are two lines on the graph >> 1) fitted logistic calibration curve >> 2) nonparametric fit using lowess >> >> Right now, the nonparametric line doesn't look very good. >> >> The "fitted logistic" line looks great. It is right next to the >> "ideal" line!! >> >> If I am understanding the graph correctly, whatever transformation >> the val.prob is doing to my predicted probability is making it really >> accurate. >> >> Is there some standard function in R that will let me do the same >> transformation? (I guess the long way around would be to tear into >> the actual val.prob function and try to reverse engineer what he's >> doing. But there must be something easier.) >> >> Anybody have any suggestions? >> >> Thanks! >> >> -N >> >> ______________________________________________ >> 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. >> > > [[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.
