On Thu, Sep 1, 2011 at 5:13 PM, Dirk Eddelbuettel <[email protected]> wrote: > Uh-oh. Factor 10. Wow.
Yeah, huh? To be fair, this example is ultra-contrived. The *only* thing that happened was indexing. Is it possible that compiler magic (ala loop unrolling that isn't done for () ) accounts for any of the speedup? I have basically no experience with this. > Matrix is different because we cannot do [i, j] for C legacy reasons. So both > variants may be fast... Yeah, but we *can* do linear access of a matrix with something like [ i+nrow*j ], which shouldn't have any bound checking (right??). I still don't see how linear bracket access on a matrix doesn't behave the same as linear bracket access on vector compared to their respective () behaviors... -xian -- A man, a plan, a cat, a ham, a yak, a yam, a hat, a canal – Panama! _______________________________________________ Rcpp-devel mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
