uniq -c
* R. Michael Weylandt <zvpunry.jrlynaqg at tznvy.pbz> [2012-10-16 16:19:27 +0100]: Have you looked at using table() directly? If I understand what you want correctly something like: table(do.call(paste, x))
I wished to avoid paste (I will have to re-split later, so it will be a performance nightmare).
Also, if you take a look at the development version of R, changes are being put in place to allow much larger data sets.
xtabs(), although dog slow, would have footed the bill nicely: --8<---------------cut here---------------start------------->8---
x <- data.frame(a=1:32,b=1:32,c=1:32,d=1:32,e=1:32) system.time(subset(as.data.frame(xtabs( ~. , x )), Freq != 0 ))
user system elapsed 12.788 4.288 17.224 --8<---------------cut here---------------end--------------->8---
you should not need "much larger data sets" for this. x is sorted.
Sam Steingold (http://sds.podval.org/) on Ubuntu 12.04 (precise) X 11.0.11103000 http://www.childpsy.net/ http://openvotingconsortium.org http://iris.org.il http://www.memritv.org http://memri.org http://think-israel.org Just because you're paranoid doesn't mean they AREN'T after you.