Solver Recording

Solver recording is useful when you want to record the iterations within a solver. The recorder can capture the values of states, errors, and residuals as the solver converges.

Option	Default	Acceptable Values	Acceptable Types	Description
excludes	[]	N/A	['list']	Patterns for vars to exclude in recording. (processed post-includes) Paths are relative to solver's Group. Uses fnmatch wildcards
includes	['*']	N/A	['list']	Patterns for variables to include in recording. Paths are relative to solver's Group. Uses fnmatch wildcards
record_abs_error	True	[True, False]	['bool']	Set to True to record absolute error at the solver level
record_inputs	True	[True, False]	['bool']	Set to True to record inputs at the solver level
record_outputs	True	[True, False]	['bool']	Set to True to record outputs at the solver level
record_rel_error	True	[True, False]	['bool']	Set to True to record relative error at the solver level
record_solver_residuals	False	[True, False]	['bool']	Set to True to record residuals at the solver level

Note

Note that the excludes option takes precedence over the includes option.

Note

The paths given in the includes and excludes options are relative to the Group that the solver is attached to.

Note

It is currently not possible to record linear solvers.

Solver Recording Example

SellarDerivatives class definition

class SellarDerivatives(om.Group):
    """
    Group containing the Sellar MDA. This version uses the disciplines with derivatives.
    """

    def setup(self):
        self.add_subsystem('d1', SellarDis1withDerivatives(), promotes=['x', 'z', 'y1', 'y2'])
        self.add_subsystem('d2', SellarDis2withDerivatives(), promotes=['z', 'y1', 'y2'])

        self.add_subsystem('obj_cmp', om.ExecComp('obj = x**2 + z[1] + y1 + exp(-y2)', obj=0.0,
                                                  x=0.0, z=np.array([0.0, 0.0]), y1=0.0, y2=0.0),
                           promotes=['obj', 'x', 'z', 'y1', 'y2'])

        self.add_subsystem('con_cmp1', om.ExecComp('con1 = 3.16 - y1', con1=0.0, y1=0.0),
                           promotes=['con1', 'y1'])
        self.add_subsystem('con_cmp2', om.ExecComp('con2 = y2 - 24.0', con2=0.0, y2=0.0),
                           promotes=['con2', 'y2'])

        self.set_input_defaults('x', 1.0)
        self.set_input_defaults('z', np.array([5.0, 2.0]))

import openmdao.api as om
from openmdao.test_suite.components.sellar_feature import SellarDerivatives

prob = om.Problem(model=SellarDerivatives())
prob.setup()

recorder = om.SqliteRecorder("cases.sql")

solver = prob.model.nonlinear_solver = om.NonlinearBlockGS()
solver.add_recorder(recorder)
solver.recording_options['record_abs_error'] = True
solver.options['use_apply_nonlinear'] = True

prob.run_model()

NL: NLBGS Converged in 7 iterations

prob.cleanup()
cr = om.CaseReader(prob.get_outputs_dir() / "cases.sql")
solver_cases = cr.list_cases('root.nonlinear_solver')

root.nonlinear_solver
rank0:root._solve_nonlinear|0|NonlinearBlockGS|0
rank0:root._solve_nonlinear|0|NonlinearBlockGS|1
rank0:root._solve_nonlinear|0|NonlinearBlockGS|2
rank0:root._solve_nonlinear|0|NonlinearBlockGS|3
rank0:root._solve_nonlinear|0|NonlinearBlockGS|4
rank0:root._solve_nonlinear|0|NonlinearBlockGS|5
rank0:root._solve_nonlinear|0|NonlinearBlockGS|6

for case_id in solver_cases:
    print(cr.get_case(case_id).abs_err)

2.2545141061171243
0.043663258684468076
0.0008635223885384846
1.707062189737485e-05
3.3746495375908125e-07
6.671260877055829e-09
1.318802844707534e-10