y=sapply(1:nrow(x), function(i) sapply(1:ncol(x), function(j) getrc(i, j)))
Arvin Zolfaghari, Ph.D. Aon Benfield | Aon Benfield Analytics 55 Bishopsgate, London, EC2N 3BD, UK t: +44 20 7522 8241 | f: +44 20 7522 3846| M: +44 78 8940 6637 e: arvin.zolfagh...@aonbenfield.com | w: www.AonBenfield.com<http://www.aonbenfield.com/> From: Arvin Zolfaghari Sent: 08 November 2010 14:35 To: 'markus.gesm...@lloyds.com' Subject: question Hi List, I am trying to apply a function to all elements of a matrix. I can use two consequent ' for' loops, but it is really slow process. I can also use the sapply as follows, but it is 10% faster, is there any other faster way (like fft)? I got a matrix of x=matrix(0,1000,2000) I want to load it with myfunction first option: For ( i in nrow(x)){ For(j in nrow(x)){ x=myfunction(i,j) }} second option: t(sapply(1:nrow(x), function(i) sapply(1:ncol(x), function(j) getrc(i, j)))) both option 1 and 2 work, but so slow. I appreciate your help. thanks Alireza [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
