Re: Question about sparsity-based implementation in MATPower

Hi Shruti, The direct linear solver used by MATLAB depends on the symmetry of the Jacobian matrix. For MATPOWER test cases that have symmetric Jacobians (due to inactive taps), a Cholesky factorization is used (LL^T = A). For cases that lead to non-symmetric Jacobian, MATLAB uses UMFPACK for

Question about sparsity-based implementation in MATPower

Greetings MATPower community, I had a question about the way sparsity-based techniques are used in the Newton-Raphson solver of the power flow algorithm in MATPower. I ran the code step-by-step and from my understanding, the way the sparsity of the Jacobian matrix is exploited is that it is

Re: Question about sparsity-based implementation in MATPower

Thank you Dr. Abhyakar, My main aim was to confirm that MATPower uses the inbuilt "\" to solve the matrix equations and not Tinney or some other form of reordering and then LU factorization followed by forward,backward substitutions. From your response I assume that it is true that MATpower uses

Re: Question about sparsity-based implementation in MATPower

Shruti, MATPOWER does use “\” operator for the linear solves. However note that, internally, MATLAB does perform some sort of matrix reordering to reduce the fill-ins in the factored matrix. For instance, UMFPACK uses an approximate minimum degree reordering scheme by default. Shri From:

Re: Question about sparsity-based implementation in MATPower

Thank you Dr. Abhyankar for the guidance. I appreciate your time and effort. Shruti On Sun, Oct 18, 2015 at 10:02 PM, Abhyankar, Shrirang G. wrote: > Shruti, > MATPOWER does use “\” operator for the linear solves. However note that, > internally, MATLAB does perform some