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 creat
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 p
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
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: Shr
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 sort of matrix reorde