[R] Speed up sum of outer products?

[AjayT]

Hi, I'm new to R and stats, and I'm trying to speed up the following sum,

for (i in 1:n){
	C = C + (X[i,] %o% X[i,])   # the sum of outer products - this is very slow
according to Rprof()		
}

where X is a data matrix (nrows=1000 X ncols=50), and n=1000. The sum has to
be calculated over 10,000 times for different X. 

I think it is similar to estimating a co-variance matrix for demeaned data
X. I tried using cov, but got different answers, and it was'nt much quicker?

Any help gratefully appreciated, 

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