PostprocessorConvergence

This Convergence derives from IterationCountConvergence and compares a Postprocessor value $var element = document.getElementById("moose-equation-156a59fb-ba09-4fde-84dd-7c1abdd6f9f7");katex.render("y", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ to a tolerance $var element = document.getElementById("moose-equation-f04b68fd-0283-4fd7-9776-4bc3c1119bfb");katex.render("\\tau", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ :

var element = document.getElementById("moose-equation-0c81ad0f-bc4b-4b5f-a8a0-7c3d290b9553");katex.render("|y| \\leq \\tau \\,.", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});

For this to work as expected, the execute_on parameter of the post-processor must include values that trigger execution before the desired check. The following table lists general recommendations for which execute_on flags to include for each type of convergence check. See SetupInterface for details on different execution points.

Convergence Check	Recommended `execute_on`
Nonlinear	`NONLINEAR_CONVERGENCE`
Steady-state	`TIMESTEP_END`
MultiApp fixed point	`MULTIAPP_FIXED_POINT_CONVERGENCE` (see Residual for specific guidance for `Residual`)
Multi-system fixed point	`MULTISYSTEM_FIXED_POINT_CONVERGENCE`

Input Parameters

postprocessorPost-processor to use for convergence criteria
C++ Type:PostprocessorName
Unit:(no unit assumed)
Controllable:No
Description:Post-processor to use for convergence criteria
toleranceTolerance to use for convergence criteria
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Tolerance to use for convergence criteria

Required Parameters

converge_at_max_iterationsFalseConverge at 'max_iterations' instead of diverging
Default:False
C++ Type:bool
Controllable:No
Description:Converge at 'max_iterations' instead of diverging
max_iterations50Maximum number of iterations
Default:50
C++ Type:unsigned int
Controllable:No
Description:Maximum number of iterations
min_iterations0Minimum number of iterations
Default:0
C++ Type:unsigned int
Controllable:No
Description:Minimum number of iterations
verboseFalseEnable printing of additional information, including convergence and divergence reasons.
Default:False
C++ Type:bool
Controllable:No
Description:Enable printing of additional information, including convergence and divergence reasons.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form

Advanced Parameters

Input Files

(test/tests/convergence/postprocessor_convergence/nonlinear.i)
(test/tests/convergence/postprocessor_convergence/multiapp_fp.i)
(test/tests/convergence/default_steady_state_convergence/pp.i)
(test/tests/multisystem/picard/nonlinearfe_nonlinearfe/multi_system.i)

(test/tests/convergence/postprocessor_convergence/nonlinear.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [u]
  []
[]

[AuxVariables]
  [w]
  []
[]

[AuxKernels]
  [w_kernel]
    type = ParsedAux
    variable = w
    expression = 'sol'
    functor_names = 'u'
    functor_symbols = 'sol'
    execute_on = 'NONLINEAR_CONVERGENCE'
  []
[]

[Kernels]
  [diff]
    type = Diffusion
    variable = u
  []
[]

[BCs]
  [left]
    type = DirichletBC
    variable = u
    boundary = left
    value = 0
  []
  [right]
    type = DirichletBC
    variable = u
    boundary = right
    value = 1
  []
[]

[Postprocessors]
  [w_change]
    type = AverageVariableChange
    variable = w
    change_over = nonlinear_iteration
    norm = L1
    execute_on = 'NONLINEAR_CONVERGENCE'
  []
  [num_nl_iterations]
    type = NumNonlinearIterations
    execute_on = 'TIMESTEP_END'
  []
[]

[Convergence]
  [test_conv]
    type = PostprocessorConvergence
    postprocessor = w_change
    tolerance = 1e-7
  []
[]

[Problem]
  previous_nl_solution_required = true
[]

[Executioner]
  type = Steady
  solve_type = 'PJFNK'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'hypre'
  nonlinear_convergence = test_conv
[]

[Outputs]
  csv = true
  show = 'num_nl_iterations'
  execute_on = 'FINAL'
[]

(test/tests/convergence/postprocessor_convergence/multiapp_fp.i)

!include ../parent.i

[Convergence]
  [fp_conv]
    type = PostprocessorConvergence
    postprocessor = nl_res
    tolerance = 1e-2
    max_iterations = 15
  []
[]

[Postprocessors]
  [nl_res]
    type = Residual
    residual_type = COMPUTE
    execute_on = 'MULTIAPP_FIXED_POINT_CONVERGENCE'
  []
[]

(test/tests/convergence/default_steady_state_convergence/pp.i)

!include base.i

[Convergence]
  [steady_conv]
    type = PostprocessorConvergence
    postprocessor = var_diff_norm
    tolerance = ${ss_tol}
  []
[]

[Postprocessors]
  [var_diff_norm]
    type = RelativeSolutionDifferenceNorm
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

(test/tests/multisystem/picard/nonlinearfe_nonlinearfe/multi_system.i)

# Solves problem in a multi-system fixed point solve.

!include base.i

[Problem]
  nl_sys_names = 'u_sys v_sys'
[]

[Variables]
  [u]
    solver_sys = u_sys
  []
  [v]
    solver_sys = v_sys
  []
[]

[Postprocessors]
  [res_norm]
    type = Residual
    residual_type = COMPUTE
    execute_on = 'MULTISYSTEM_FIXED_POINT_CONVERGENCE'
  []
[]

[Convergence]
  [u_conv]
    type = DefaultNonlinearConvergence
    nl_abs_tol = 1e-8
    nl_rel_tol = 1e-8
    nl_max_its = 10
  []
  [v_conv]
    type = DefaultNonlinearConvergence
    nl_abs_tol = 1e-8
    nl_rel_tol = 1e-8
    nl_max_its = 10
  []
  [fp_conv]
    type = PostprocessorConvergence
    postprocessor = res_norm
    tolerance = 1e-8
    max_iterations = 10
    verbose = true
  []
[]

[Executioner]
  nonlinear_convergence = 'u_conv v_conv'
  multi_system_fixed_point = true
  multi_system_fixed_point_convergence = fp_conv
[]

[Outputs]
  file_base = multi_system
[]

Input Parameters
Input Files