factorizations using SMPSs

a r t i c l e i n f o ð1Þ and engin r solution c in a direct method that first decomposes A into a simpler form, and then solves the corresponding transformed sys well-known decomposition for the solution of (1), when the coefficient matrix A is symmetric positive definite (s. the Cholesky factorization. Computing this factorization requires a cubic number of floating-point arithmetic operation