Label ECDF plot points

Question

I'm trying to label the points of an ECDF plot with another column from my data field. Currently I'm using this:

untouched = read.table("results-untouched.tsv", sep="\t")
plot.ecdf(untouched$V4, xlim=c(0.75,1.25), ylim=c(0,1), col='green', verticals=T)

which plots allright, but I'm then unable to add the labels to the points. The labels would be in untouched$V1.

Any idea on how to do this?

Answer 1

To add labels, you can use the text function. For example, we generate some data

x = sort(rnorm(10))

then create the ecdf object (plot.ecdf does this automatically),

m = ecdf(x)

and plot m

plot(m)

To add labels, we use the text function. The x coordinates are the data, the y coordinates are the output from the ecdf function (with an additional 0.03 to avoid over-plotting):

text(x, m(x) + 0.03, LETTERS[1:10])