MATLAB: Symbolic factorization of a large sparse matrix

MATLABsymbolic factorization

I'm solving a series of problems Ax=b, where A changes, but still has the same sparsity pattern. To exploit that, in the initialization, I only perform symbolic factoriazation once.
Currently, I use pardiso:
https://www.mathworks.com/matlabcentral/answers/497401-pardiso-reuse-symbolic-factorization
I was wondering how come matlab doesn't offer something like this, considering that the mldivide (based on Tim Davis's SuiteSparse) is supposed to be the fastest option?

Best Answer

  1. When a symmetric matrix (Hessian) is involved, MA57 is used (ldl), which is faster than suitesparse.
  2. The symbolic factorization is actully the reordering that produces sparser factors. It's don't by default with amd (metis is another option).
Related Question