data frame subset patch, take 2
On Wednesday 13 December 2006 1:23 pm, Marcus G. Daniels wrote:
Vladimir Dergachev wrote:
2. It would be nice to have true hashed arrays in R (i.e. O(1) access times). So far I have used named lists for this, but they are O(n):
new.env(hash=TRUE) with get/assign/exists works ok. But I suspect its just too easy to use named lists because it is easy, and that has bad performance ramifications for user code (perhaps the R developers are more vigilant about this for the R code itself).
Cool, thank you !
I wonder whether environments could be extended to allow names() to work
(altough I see that ls() does the same function) and to allow for(i in E)
loops.
thank you
Vladimir Dergachev