But isn't it change multiplication order? WBR Dima
2010/6/29 <bill.venab...@csiro.au> > Since X is a vector, then > > A <- sum(X, solve(V, X)) > > is probably slightly better here. > > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > On Behalf Of Dmitrij Kudriavcev > Sent: Tuesday, 29 June 2010 12:29 PM > To: r-help@r-project.org > Subject: [R] Matrix operations > > Hello > > I have a quick question. > > I need to compute matrix in R, like A <- t(X) %*% solve(V) %*% X, where X > is > a vector and V is a matrix > > This code works, but now i want to optimize it. I have try: > > A <- crossprod(X, solve(V)) %*% X > > Is there another, better way? > > WBR > Dima > > [[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. > [[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.
