LSOLVER
The LSOLVER command allows the user to change the linear solver used by the Adams Solver (FORTRAN). The linear solver is invoked multiple times throughout the simulation to compute corrections in the system state.
Format
Arguments
CALAHAN | Specifies that Adams Solver (FORTRAN) is to use the CALAHAN solver exclusively. The Calahan solver is usually faster than the Harwell solver, but it cannot analyze systems with redundant constraints. |
HARWELL | Specifies that Adams Solver (FORTRAN) is to use the HARWELL solver exclusively. The Harwell solver can analyze systems with redundant constraints, but it is usually slower than the Calahan solver. |
Tip: | The CALAHAN and HARWELL solvers use somewhat different strategies for picking pivots during the linear solution. If one solver is experiencing difficulties solving an ill-conditioned model, you may try the other solver. One may work better on a particular model than the other. |
Caution: | Even though you deactivate all your redundant constraints, Adams Solver (FORTRAN) does not allow you to use the Calahan solver. If (under these circumstances) you issue the LSOLVER/CALAHAN command, Adams Solver (FORTRAN) returns the message: Changing to the CALAHAN solver is not allowed for this model due to the presence of redundant constraints. To avoid this problem, deactivate all your redundant constraints, run a short simulation, and then issue the LSOLVER/CALAHAN command. |
See other Analysis parameters available.