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
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