Thank you Jim for your answer.Ok alpha( it is the speed of the boat) is a range of number from 0.5 to 10 like 0.5,1,1.5,2...., I would like to have the mean of x and y base on each value of alpha, because I have like ten numbers of x for each value of speed, thats why I want the mean of that and them i could create the roc plot with the new values. I would say that alpha values are ordered already?
Thanks , Marta 2014-07-03 1:17 GMT+02:00 Jim Lemon <j...@bitwrit.com.au>: > 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 > > [[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.