On Wed, 2 Jul 2014 02:42:31 PM Marta valdes lopez wrote: > Hello, > > I run this script , because i would like to do the mean of x and y base on > alpha as factor. > > > library(xlsx) > library(ROCR > filename<-"amanhecer roc.csv" > rocdata<- read.table(filename, sep=";",header=TRUE,dec=",") > > rocdata$alpha.15_12 <- as.factor(rocdata$alpha.15_12) > > TPaverage <- tapply(rocdata$y.15_12, rocdata$alpha.15_12, mean) > FPaverage <- tapply(rocdata$x.15_12, rocdata$alpha.15_12, mean) > > ###And them with the new data i want to create a plot, kind of ROC plot. > > Anthias<-rocdata > str(Anthias) > data(ROCR.simple) > pred <- prediction( ROCR.simple$predictions, ROCR.simple$labels ) > perf <- performance( pred, "tpr", "fpr" ) > windows(width = 9.5, height = 10.50) > par(mfrow = c(1,1)) > > cc<-Anthias[1] > ee<-Anthias[2] > aa<-Anthias[3] > p...@x.name<-"FP" > p...@y.name<-"TP" > p...@alpha.name<-"Speed" > bb<-data.frame(aa) > perf@x.values<-bb > dd<-data.frame(cc) > perf@y.values<-dd > ff<-data.frame(ee) > perf@alpha.values<-ff > > plot(perf, main="Teste", colorize=TRUE, coloraxis.at=c(0,2,4,6,8,10), > coloraxis.cex.axis=0.8, colorize.palette=(rainbow(256,start=0, end=0.7)), > lwd=7, colorkey.relwidth=0.4, yaxis.las=1) > > But after run the whole script i got the error:max not meaningful for > factors, anyone can help me? I am a beginner in R ,so sorry if this is > wasting anyone's time*.* > Hi Marta, The error message is straightforward. Somewhere in one of the functions you have called, the "max" function is applied to your factor variable. The definition of factor variables is that the the actual values are of nominal class, in which there is no meaningful ordering of values, therefore the maximum value is undefined. You could try as.numeric(alpha), but that is dangerous as it depends on whether the sorting of values (default alphabetic) is what you want. If we knew what "alpha" was, it would help.
Jim ______________________________________________ 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.
