My question: Are there equivalents to colSums in R?
I don't think there are functions for doing this, but you can speed up things a lot by using matrix operations instead of apply if this is possible:
x <- matrix(rnorm(1E5),ncol=100) system.time(tmp1 <- apply(x,2,sum))
[1] 0.04 0.01 0.05 0.00 0.00
system.time(tmp2 <- c(rep(1,nrow(x))%*%x))
[1] 0.01 0.00 0.01 0.00 0.00
all.equal(tmp1,tmp2)
[1] TRUE Yours, Marcel Wolbers
Marcel Wolbers, LEO C14, Seminar for Statistics, ETH Zurich CH-8092 Zurich, Switzerland; phone: (01) 632 2252 -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help 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-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._