Solver packages (PCG, SOR, SIP, DSP)¶

One of the following solvers must be specified for a model run. All arguments for the solver are non-spatial values.

You can check whether a Modflow run converged or not with

res = mf.converged()

PCG package¶

The preconditioned conjugate-gradient package can be enabled with

mf.setPCG(MXITER, ITERI, NPCOND, HCLOSE, RCLOSE, RELAX, NBPOL, DAMP)

where

MXITER: is the maximum number of outer iterations;
ITERI: is the number of inner iterations;
NPCOND: 1 - Modified Incomplete Cholesky, 2 - Polynomial matrix conditioning method;
HCLOSE: is the head change criterion for convergence;
RCLOSE: is the residual criterion for convergence;
RELAX: is the relaxation parameter used with NPCOND = 1;
NBPOL: indicates whether the estimate of the upper bound on the maximum eigenvalue is 2.0 and
DAMP: is the damping factor.

The slice-successive overrelaxation package can be enabled with

mf.setSOR(MXITER, ACCL, HCLOSE)

where

The strongly implicit procedure package can be enabled with

mf.setSIP(MXITER, NPARAM, ACCL, HCLOSE, IPCALC, WSEED)

where

MXITER: is the maximum number of times through the iteration loop in one time step;
NPARAM: is the number of iteration variables to be used;
ACCL: is the acceleration variable;
IPCALC: 0 - the seed entered by the user will be used, 1 - the seed will be calculated at the start of the simulation, and
WSEED: is the seed for calculating iteration variables.

The direct solver package can be enabled with

mf.setDSP(ITMX, MXUP, MXLOW, MXBW, IFREQ, ACCL, HCLOSE)

where

ITMX: is the maximum number of iterations each time step;
MXUP: is the maximum number of equations in the upper part of the equations to be solved;
MXLOW: is the maximum number of equations in the lower part of equations to be solved;
MXBW: is the maximum band width plus 1 of the [AL] matrix;
IFREQ: is flag indicating the frequency at which coefficients in [A] change;
ACCL: is a multiplier for the computed head change for each iteration and
HCLOSE: is the head change closure criterion.