[R] ecdf plots, lines, and y values
ligges at statistik.uni-dortmund.de
Thu Jun 3 21:36:48 CEST 2004
Monica Palaseanu-Lovejoy wrote:
> I have a question for the group, perhaps someone can help me
> figure this out. I've already looked in the help files and they were
> no help to me.
> I have a vector of values and I am plotting an ecdf graph.
> 1. How can i draw a continuous line through the ecdf points? (lines
> and type for the plot with an ecdf object does not work)
Well, the help page ?plot.ecdf and ?plot.stepfun is pretty clear and
tells us to use verticals = TRUE.
From the help page:
F10 <- ecdf(rnorm(10))
plot(F10, verticals = TRUE, do.p = FALSE)
> 2. Supposing I have this line drawn. I can add a vertical line of a
> known x value which intersects the graph. How can I determine the
> y value of the graph point that is intersected by the abline?
Use knots(), e.g. by extending the former example as follows:
kF10 <- knots(F10)
sum(kF10 <= x) / length(kF10)
> Any help would be appreciated.
> Thanks in advance,
> R-help at stat.math.ethz.ch mailing list
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
More information about the R-help