I need to solve a linear equation Ax=b for 7000 times (A is sparse and complex square matrix), and at each time only 4 elements (A(i,k), A(i,m), A(j,k) and A(j,m)) are changed while all other elements are the same (at each time the indices i,j,k,m are different). I used block to obtain the updated inverse of matrix A. The total CPU time is more than 20 minutes. I am wondering if there is a faster way to solve this equation and control the CPU time within 1 minute.
Thanks a lot in advance.
Benson from Texas