jxbz

""" Computing zeroth matrix powers via Lakic 1998.
paper: "On the Computation of the Matrix k-th Root"

Suppose we have a matrix G = USV^T and we want to compute
G^0 defined via G^0 = UV^T. We might want to do this to run
"stochastic spectral descent" of Carlson et al 2015. The
naive way to do this is via the SVD. But we can also just do
(GG^T)^(-1/2) G or alternatively G (G^TG)^(-1/2) and apply
the iterative method from Lakic 1998.