Hello, I would like to do Block LDL' factorization for Hermitian indefinite matrices, where D is a block diagonal matrix and L a "psychologically lower triangular matrix" (i.e a product of unit lower triangular and permutation matrices) in L such that A = L*D*L'. The block diagonal matrix D has 1-by-1 and 2-by-2 blocks on its diagonal. Does anybody know how to do this in R? Thank you Felipe Parra [[alternative HTML version deleted]]