Hello,
I'veI have a SPDsymmetric positive definite (SPD) matrix A; which$A$ that needs to be factorized as ${A=SS^{T}}$. ButHowever, using the Cholesky decomposition for this purpose is prohibitive in terms of computational cost. Moreover, the matrix is Densedense and has a slow decaying eigen-spectrum.
Can anything be suggested for replacement of cholesky.Cholesky?
Moreover, it need not be exact,anything. Anything approximate will work as long as $y=Sz$ and the quantity $y^{T}y$ is what I'mI am trying to preserve.(, where $z$ is standard normal vector)
Thanks.