Select a suitable iterative method to solve a system.
Sparse Iterative methods solve Ax = b through an iterative process that only requires multiplication by A or Aᵀ. However, if A is numerically difficult, the iterative process may fail to converge to a solution. Further, even for problems where the process converges, it may do so slowly. Both of these issues can be fixed through the application of a problem-specific preconditioner that cheaply approximates the inverse of A.