From: <meytar_at_techunix.technion.ac.il>

Date: Mon, 28 Mar 2011 12:35:16 +0200

Date: Mon, 28 Mar 2011 12:35:16 +0200

Hello

I am trying to make a graph of 10 different lines built each from 4 different
segments and to add a darker line that will represent the average of all graphs
- all in the same plot.Actually each line is a ROC plot
The code I'm using for plotting one line is as follows:

logit.roc.plot <- function(r, title="ROC curve") {
old.par <- par(no.readonly = TRUE); on.exit(par(old.par))
par(xaxs="i", yaxs="i")

plot(1 - r$spec, r$sens, xlim=c(0, 1), ylim=c(0,1), type="l",
xlab="(1 - specificity): false positive rate",
ylab="sensitivity: true positive rate",

col="grey82", lwd=2);

points(1 - r$spec, r$sens,pch=20, cex=1.5, col="grey82")
abline(0, 1, lty=2);

segments(1-r$spec, 1-r$spec, 1-r$spec, r$sens, lty=3)
#text(1 - max(r$spec,na.rm=T),

r$sens[which.max(r$spec)],r$pts[which.max(r$spec)],pos=2,cex=0.8)
text(0, 0.9, paste("Area under ROC:",round(logit.roc.area(r),4)), pos=4)
title(main = title)

}

r[5,]=c(0,0,1,10)

logit.roc.plot(r)

r=r[-5,]

text(1 - max(r$spec,na.rm=T),

r$sens[which.max(r$spec)],r$pts[which.max(r$spec)],pos=2,cex=0.8)

while r is a MATRIX (4x4) with

colnames=c("pts",sens","spec",iterationnumber.")
and I have for each ROC curve a different matrix but all matrices have the same
size. (They are organized as a list of 10 matrices by the size 4X4 each)

Would appreciate your help in putting all ROC curves on the same plot. Thank you

-- Meytar ______________________________________________ R-help_at_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.Received on Mon 28 Mar 2011 - 12:40:00 GMT

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