I think you are referring to the same step? QR decomposition is how you
solve for u_i which is what I imagine the same step you have in mind.
Computing an inverse is more costly than solving a linear system via QR
decompostion.
On 15.03.2013 11:41, Dominik Hübner wrote:
> I was recently having a look at the ALS-WR factorisation code. Why is there a
> QR decomposition before computing u_i or m_j instead of multiplying the
> inverse of
I was recently having a look at the ALS-WR factorisation code. Why is there a
QR decomposition before computing u_i or m_j instead of multiplying the inverse
of A_i with V_i straightaway? (reference to these two classes
https://github.com/apache/mahout/blob/trunk/math/src/main/java/org/apache/ma
