[EMAIL PROTECTED] wrote: > Hi, > > x and y are (numeric) vectors. I wonder if one of the following is more > efficient than the other: > > x%*%y > > or > > sum(x*y) > ?
I'd try x <- rnorm(1000000) y <- rnorm(1000000) system.time(x%*%y) system.time(sum(x*y)) and finally (hint, hint!): system.time(crossprod(x, y)) Uwe Ligges > Thanks, > Dimitri Szerman > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
