Don't know if its any faster but try this: Reduce("%*%", list(M1, M2, M3), accumulate = TRUE)
On Thu, Oct 29, 2009 at 9:56 AM, Todd Schneider <todd.w.schnei...@gmail.com> wrote: > Hi all, > > I am looking for a function like cumprod() that works for matrix > multiplication. > > In other words, I have matrices [M1, M2, ..., Mn], and I want to calculate > [M1, M1%*%M2, M1%*%M2%*%M3, ..., M1%*%...%*%Mn] as quickly as possible. > Right now I'm using a for() loop but it seems like there should be a faster > way. > > Any help is appreciated! > > Thanks, > > Todd Schneider > todd.w.schnei...@gmail.com > > [[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. > ______________________________________________ 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.