...and this is where we cue the informative article on least squares
calculations in R by Doug Bates:

http://cran.r-project.org/doc/Rnews/Rnews_2004-1.pdf

HTH,
Dennis

On Tue, Mar 1, 2011 at 10:52 AM, AjayT <ajaytalati@googlemail.com> wrote:

> Hey thanks alot guys !!! That really speeds things up !!! I didn't know %*%
> and crossprod, could operate on matrices. I think you've saved me hours in
> calculation time. Thanks again.
>
> > system.time({C=matrix(0,50,50);for(i in 1:n)C = C + (X[i,] %o% X[i,])})
>   user  system elapsed
>    0.45    0.00    0.90
> > system.time({C1 = t(X) %*% X})
>   user  system elapsed
>    0.02    0.00    0.05
> > system.time({C2 = crossprod(X)})
>   user  system elapsed
>   0.02    0.00    0.02
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/Speed-up-sum-of-outer-products-tp3330160p3330378.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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]]

