Skip to content

chull() wanted?

2 messages · Dipl.-Stat. Detlef Steuer, Brian Ripley

Original
Dipl.-Stat. Detlef Steuer
# 
Hello!

Is there someone already working on an implementation of Splus'
chull() function for R?
If not, I would like volunteer to try it.

For my "Diplom" I implemented convex peeling in C (some time ago),
 using an O(n log(n)) algorithm, so it probably will prove relatively easy to
use that code for a R-function.

Well, as least as easy as any programming tends to be. :-)  

Detlef Steuer



Detlef Steuer Universitaet Dortmund                             ///////
LS Computergestuetzte Statistik                          U N I D O ///  
steuer@amadeus.statistik.uni-dortmund.de                ______///////  
Tel: ++49 +231 755 4353 Fax: ++49 +231 755 4387         \_\_\_\/////
                                                         \_\_\_\///
                                                          \_\_\_\/

*** Use what talents you possess: the woods would be very silent ***
*** if no birds sang there except those that sang best.          ***
*** Henry Van Dyke                                               ***
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Brian Ripley
#
On Wed, 7 Apr 1999, Dipl.-Stat. Detlef Steuer wrote:

            

      
      
      
    

        
If only you had volunteered a month ago!

There is one implementation in package sm, and a cleaner one in 0.64, due
out today.  Both as versions of Eddy's 1977 algorithm. I would be happy to
replace the present chull by something better, though. It doesn't do
peeling, but that is easy to arrange in R: just remove the convex hull and
repeat.