Outer product function?

[Jesse Wursten]

Is there an outer product equivalent to cross()? As in, cross calculates X'X efficiently, is there something similar for XX'?

[Christophe Kolodziejczyk]

No, I haven't seen such a function. You don't give details about why or in which context you want to compute the outer product. Depending on the nature of the problem you might be able to avoid the computation of this matrix, which can be huge.