Convergence/Divergence Criteria

The iparm[S3L_iter_conv] parameter selects the criterion to be used for stopping computation. Currently, the single valid option for this parameter is S3L_r0, which selects the default criterion for both convergence and divergence. The convergence criterion is satisfied when:

err = ||rj||_2 / ||r0||_2 < epsilon

and the divergence criterion is met when

err = ||rj||_2 / ||r0||_2 > 10000.0

where:

• rj and r0 are the residuals obtained at iterations j and 0.

• ||.||_2 is the 2-norm.

• epsilon is the desired convergence tolerance stored in rparm[S3L_iter_tol].

• 10000.0 is the divergence tolerance, which is set internally in the solver.