[R] R function for percentrank

[Martin Maechler]

>>>>> "MS" == Marc Schwartz <marc_schwartz at comcast.net>
>>>>>     on Wed, 05 Dec 2007 12:43:50 -0600 writes:

[............]

    MS> Martin,

    MS> Thanks for the corrections. In hindsight, now seeing the intended use of
    MS> ecdf() in the fashion you describe above, it is now clear that my
    MS> approach in response to David's query was un-needed and "over the top".
    MS> "Yuck" is quite appropriate... :-)

    MS> As I was going through this "exercise", it did seem overly complicated,
    MS> given R's usual elegant philosophy about such things. I suppose if I had
    MS> looked at the source for plot.stepfun(), it would have been more evident
    MS> as to how the y values are acquired.

    MS> In reviewing the examples in ?ecdf, I think that an example using
    MS> something along the lines of the discussion here more explicitly, would
    MS> be helpful. It is not crystal clear from the examples, that one can use
    MS> ecdf() in this fashion, though the use of "12 * Fn(tt)" hints at it.

    MS> Perhaps:

    MS> ##-- Simple didactical  ecdf  example:
    MS> x <- rnorm(12)
    MS> Fn <- ecdf(x)
    MS> Fn
    MS> Fn(x)  # returns the percentiles for x
    MS> ...

Thank you, Marc for the above proposal, to make the examples
more "crystal clear" :-) 
I've now amended the R-devel version of  help(ecdf) accordingly.

    MS> Thanks again Martin and no offense taken...  :-)

I'm glad. You're welcome!
Martin