ParsedConvergence

This Convergence allows the user to specify arbitrary expressions for convergence and divergence criteria. These expressions ("convergence_expression" and "divergence_expression") may contain any of the following:

Convergence objects
Functions
Post-processors
Constant values

The expressions are parsed using the Function Parser syntax. The full library of mathematical operators is valid in the parsed expression, but for convenience, we list some of the logical and comparison operators here:

Syntax	Description
`()`	Parentheses for order of operations
`!A`	NOT `A`
`A & B`	`A` AND `B`
`A` I `B`	`A` OR `B`
`A = B`	`A` EQUALS `B`
`A != B`	`A` DOES NOT EQUAL `B`
`A >= B`	`A` GREATER THAN OR EQUAL TO `B`

The expressions must evaluate to either 1 or 0, which correspond to true or false, respectively; if the expression returns another value, an error results. Note the following rules for the Convergence object values:

For the convergence expression, Convergence objects evaluate to true if they are CONVERGED and false otherwise (ITERATING or DIVERGED).
For the divergence expression, Convergence objects evaluate to true if they are DIVERGED and false otherwise (ITERATING or CONVERGED).

The divergence expression is optional. If omitted, divergence occurs if any of the supplied Convergence objects return DIVERGED, e.g.,


divergence_expression = 'conv1 | conv2 | conv3'

if "symbol_values" contains conv1, conv2, and conv3.

Input Parameters

convergence_expressionExpression to parse for convergence
C++ Type:FunctionExpression
Unit:(no unit assumed)
Controllable:No
Description:Expression to parse for convergence

Required Parameters

divergence_expressionExpression to parse for divergence
C++ Type:FunctionExpression
Unit:(no unit assumed)
Controllable:No
Description:Expression to parse for divergence
epsilon0Fuzzy comparison tolerance
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Fuzzy comparison tolerance
symbol_namesSymbol names to use in the parsed expressions
C++ Type:std::vector<std::string>
Controllable:No
Description:Symbol names to use in the parsed expressions
symbol_valuesValues (Convergence names, Postprocessor names, Function names, and constants) corresponding to each entry in 'symbol_names'
C++ Type:std::vector<std::string>
Controllable:No
Description:Values (Convergence names, Postprocessor names, Function names, and constants) corresponding to each entry in 'symbol_names'
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

disable_fpoptimizerFalseDisable the function parser algebraic optimizer
Default:False
C++ Type:bool
Controllable:No
Description:Disable the function parser algebraic optimizer
enable_ad_cacheTrueEnable caching of function derivatives for faster startup time
Default:True
C++ Type:bool
Controllable:No
Description:Enable caching of function derivatives for faster startup time
enable_auto_optimizeTrueEnable automatic immediate optimization of derivatives
Default:True
C++ Type:bool
Controllable:No
Description:Enable automatic immediate optimization of derivatives
enable_jitTrueEnable just-in-time compilation of function expressions for faster evaluation
Default:True
C++ Type:bool
Controllable:No
Description:Enable just-in-time compilation of function expressions for faster evaluation
evalerror_behaviornanWhat to do if evaluation error occurs. Options are to pass a nan, pass a nan with a warning, throw a error, or throw an exception
Default:nan
C++ Type:MooseEnum
Options:nan, nan_warning, error, exception
Controllable:No
Description:What to do if evaluation error occurs. Options are to pass a nan, pass a nan with a warning, throw a error, or throw an exception

Parsed Expression Advanced Parameters

Input Files

(test/tests/convergence/reference_residual_convergence/custom_residual.i)
(test/tests/convergence/reference_residual_convergence/formatting.i)
(modules/combined/test/tests/reference_residual/contact.i)
(test/tests/convergence/multi_postprocessor_convergence/multi_postprocessor_convergence.i)
(test/tests/time_steppers/iteration_adaptive/adapt_linear_systems.i)
(test/tests/convergence/parsed_convergence/base.i)

(test/tests/convergence/reference_residual_convergence/custom_residual.i)

coef=1

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 2
[]

[Problem]
  # type = ReferenceResidualProblem
  extra_tag_vectors = 'u_ref u_res v_ref v_res'
[]

[Variables]
  [u][]
  [v][]
[]

[Kernels]
  [u_diff]
    type = CoefDiffusion
    variable = u
    coef = 1
    extra_vector_tags = 'u_res'
  []
  [u_rxn]
    type = PReaction
    variable = u
    coefficient = 1
    power = 2
    extra_vector_tags = 'u_res'
  []
  [u_f]
    type = BodyForce
    variable = u
    value = 1
    extra_vector_tags = 'u_res'
  []
  [v_diff]
    type = Diffusion
    variable = v
    extra_vector_tags = 'v_res'
  []
  [v_rxn]
    type = PReaction
    variable = v
    coefficient = 1
    power = 2
    extra_vector_tags = 'v_res'
  []
  [v_f]
    type = BodyForce
    variable = v
    value = 1
    extra_vector_tags = 'v_res'
  []
[]

[BCs]
  [u]
    type = RobinBC
    boundary = 'left right'
    coef = ${coef}
    variable = u
    extra_vector_tags = 'u_ref u_res'
  []
  [v]
    type = RobinBC
    boundary = 'left right'
    coef = 1
    variable = v
    extra_vector_tags = 'v_ref v_res'
  []
[]

[Convergence]
  [u_conv]
    type = ReferenceResidualConvergence
    reference_vector = 'u_ref'
    residual_vector = 'u_res'
  []
  [v_conv]
    type = ReferenceResidualConvergence
    reference_vector = 'v_ref'
    residual_vector = 'v_res'
  []
  [conv]
    type = ParsedConvergence
    convergence_expression = 'u_conv & v_conv'
    symbol_names = 'u_conv v_conv'
    symbol_values = 'u_conv v_conv'
  []
[]

[Executioner]
  type = Steady
  nonlinear_convergence = conv
[]

[Outputs]
  exodus = true
[]

(test/tests/convergence/reference_residual_convergence/formatting.i)

scaling = false

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 2
[]

[GlobalParams]
  absolute_value_vector_tags = 'ref'
[]

[Problem]
  extra_tag_vectors = 'ref'
[]

[Variables]
  [a]
  []
  [b]
  []
  [c]
  []
  [d]
  []
  [verylongvariable_e]
  []
  [variable_f]
  []
  [g]
  []
[]

[Kernels]
  [a_force]
    type = BodyForce
    variable = a
    value = 1e2
  []
  [b_force]
    type = BodyForce
    variable = b
    value = 1e3
  []
  [c_force]
    type = BodyForce
    variable = c
    value = 1e4
  []
  [d_force]
    type = BodyForce
    variable = d
    value = 1e5
  []
  [e_force]
    type = BodyForce
    variable = verylongvariable_e
    value = 1e6
  []
  [f_force]
    type = BodyForce
    variable = variable_f
    value = 1e7
  []
  [g_force]
    type = BodyForce
    variable = g
    value = 1e8
  []

  [a_dt]
    type = TimeDerivative
    variable = a
  []
  [b_dt]
    type = TimeDerivative
    variable = b
  []
  [c_dt]
    type = TimeDerivative
    variable = c
  []
  [d_dt]
    type = TimeDerivative
    variable = d
  []
  [e_dt]
    type = TimeDerivative
    variable = verylongvariable_e
  []
  [f_dt]
    type = TimeDerivative
    variable = variable_f
  []
  [g_dt]
    type = TimeDerivative
    variable = g
  []
[]

[BCs]
  [a_bc]
    type = DirichletBC
    variable = a
    boundary = 'left right'
    value = 1
  []
  [b_bc]
    type = DirichletBC
    variable = b
    boundary = 'left right'
    value = 1
  []
  [c_bc]
    type = DirichletBC
    variable = c
    boundary = 'left right'
    value = 1
  []
  [d_bc]
    type = DirichletBC
    variable = d
    boundary = 'left right'
    value = 1
  []
  [e_bc]
    type = DirichletBC
    variable = verylongvariable_e
    boundary = 'left right'
    value = 1
  []
  [f_bc]
    type = DirichletBC
    variable = variable_f
    boundary = 'left right'
    value = 1
  []
  [g_bc]
    type = DirichletBC
    variable = g
    boundary = 'left right'
    value = 1
  []
[]

[Convergence]
  [conv_one]
    type = ReferenceResidualConvergence
    reference_vector = 'ref'
    group_variables = 'a b variable_f; c d'
    converge_on = 'a b variable_f c d g'
    nl_rel_tol = 1e-9
    unscale_the_residual = ${scaling}
  []
  [conv_two]
    type = ReferenceResidualConvergence
    reference_vector = 'ref'
    converge_on = 'verylongvariable_e g'
    nl_rel_tol = 1e-9
    unscale_the_residual = ${scaling}
    normalization_type = LOCAL_L2
  []
  [combined]
    type = ParsedConvergence
    convergence_expression = 'conv_one & conv_two'
    symbol_names = 'conv_one conv_two'
    symbol_values = 'conv_one conv_two'
  []
[]

[Executioner]
  type = Transient
  num_steps = 1
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
  line_search = none
  nonlinear_convergence = combined
  verbose = true
  automatic_scaling = ${scaling}
[]

[Outputs]
  exodus = true
[]

[Postprocessors]
  [a_avg]
    type = ElementAverageValue
    variable = a
  []
  [b_avg]
    type = ElementAverageValue
    variable = b
  []
  [c_avg]
    type = ElementAverageValue
    variable = c
  []
  [d_avg]
    type = ElementAverageValue
    variable = d
  []
  [e_avg]
    type = ElementAverageValue
    variable = verylongvariable_e
  []
  [f_avg]
    type = ElementAverageValue
    variable = variable_f
  []
[]

(modules/combined/test/tests/reference_residual/contact.i)

AD = ''
use_ad = false
temp_scaling = 1
disp_x_scaling = ${fparse 1 / temp_scaling}

[GlobalParams]
  order = FIRST
  displacements = 'disp_x disp_y'
[]

[Problem]
  extra_tag_vectors = 'constraint_res kernel_res constraint_ref kernel_ref absolute_ref total_res'
[]

[Mesh]
  [gen]
    type = CartesianMeshGenerator
    dim = 2
    dx = '1 0.01 1'
    dy = 1
    ix = '5 1 5'
    iy = '20'
    subdomain_id = '0 1 2'
  []
  [rename]
    type = RenameBlockGenerator
    input = gen
    old_block = '0 1 2'
    new_block = 'a b c'
  []
  [sidesets_a]
    type = SideSetsBetweenSubdomainsGenerator
    input = rename
    new_boundary = a_right
    paired_block = b
    primary_block = a
  []
  [sidesets_c]
    type = SideSetsBetweenSubdomainsGenerator
    input = sidesets_a
    new_boundary = c_left
    paired_block = b
    primary_block = c
  []
  [delete]
    type = BlockDeletionGenerator
    input = sidesets_c
    block = b
  []

  patch_update_strategy = always
  coord_type = RZ
[]

[Variables]
  [temp]
    initial_condition = 298
    scaling = ${temp_scaling}
  []
  [disp_x]
    scaling = ${disp_x_scaling}
  []
  [disp_y]
  []
[]

[AuxVariables]
  [constraint_res_temp]
  []
  [constraint_res_disp_x]
  []
  [constraint_res_disp_y]
  []
  [kernel_res_temp]
  []
  [kernel_res_disp_x]
  []
  [kernel_res_disp_y]
  []

  [constraint_ref_temp]
  []
  [constraint_ref_disp_x]
  []
  [constraint_ref_disp_y]
  []
  [kernel_ref_temp]
  []
  [kernel_ref_disp_x]
  []
  [kernel_ref_disp_y]
  []

  [absolute_ref_temp]
  []
  [absolute_ref_disp_x]
  []
  [absolute_ref_disp_y]
  []
  [total_res_temp]
  []
  [total_res_disp_x]
  []
  [total_res_disp_y]
  []
[]

[AuxKernels]
  [constraint_res_temp_aux]
    type = TagVectorAux
    variable = constraint_res_temp
    v = temp
    vector_tag = constraint_res
  []
  [constraint_res_disp_x_aux]
    type = TagVectorAux
    variable = constraint_res_disp_x
    v = disp_x
    vector_tag = constraint_res
  []
  [constraint_res_disp_y_aux]
    type = TagVectorAux
    variable = constraint_res_disp_y
    v = disp_y
    vector_tag = constraint_res
  []
  [kernel_res_temp_aux]
    type = TagVectorAux
    variable = kernel_res_temp
    v = temp
    vector_tag = kernel_res
  []
  [kernel_res_disp_x_aux]
    type = TagVectorAux
    variable = kernel_res_disp_x
    v = disp_x
    vector_tag = kernel_res
  []
  [kernel_res_disp_y_aux]
    type = TagVectorAux
    variable = kernel_res_disp_y
    v = disp_y
    vector_tag = kernel_res
  []

  [constraint_ref_temp_aux]
    type = TagVectorAux
    variable = constraint_ref_temp
    v = temp
    vector_tag = constraint_ref
  []
  [constraint_ref_disp_x_aux]
    type = TagVectorAux
    variable = constraint_ref_disp_x
    v = disp_x
    vector_tag = constraint_ref
  []
  [constraint_ref_disp_y_aux]
    type = TagVectorAux
    variable = constraint_ref_disp_y
    v = disp_y
    vector_tag = constraint_ref
  []
  [kernel_ref_temp_aux]
    type = TagVectorAux
    variable = kernel_ref_temp
    v = temp
    vector_tag = kernel_ref
  []
  [kernel_ref_disp_x_aux]
    type = TagVectorAux
    variable = kernel_ref_disp_x
    v = disp_x
    vector_tag = kernel_ref
  []
  [kernel_ref_disp_y_aux]
    type = TagVectorAux
    variable = kernel_ref_disp_y
    v = disp_y
    vector_tag = kernel_ref
  []

  [absolute_ref_temp_aux]
    type = TagVectorAux
    variable = absolute_ref_temp
    v = temp
    vector_tag = absolute_ref
  []
  [absolute_ref_disp_x_aux]
    type = TagVectorAux
    variable = absolute_ref_disp_x
    v = disp_x
    vector_tag = absolute_ref
  []
  [absolute_ref_disp_y_aux]
    type = TagVectorAux
    variable = absolute_ref_disp_y
    v = disp_y
    vector_tag = absolute_ref
  []
  [total_res_temp_aux]
    type = TagVectorAux
    variable = total_res_temp
    v = temp
    vector_tag = total_res
  []
  [total_res_disp_x_aux]
    type = TagVectorAux
    variable = total_res_disp_x
    v = disp_x
    vector_tag = total_res
  []
  [total_res_disp_y_aux]
    type = TagVectorAux
    variable = total_res_disp_y
    v = disp_y
    vector_tag = total_res
  []
[]

[Physics/SolidMechanics/QuasiStatic]
  [all]
    block = 'a c'
    strain = FINITE
    eigenstrain_names = 'thermal_strain'
    temperature = temp
    use_automatic_differentiation = ${use_ad}
    volumetric_locking_correction = true
    extra_vector_tags = 'kernel_res total_res'
    absolute_value_vector_tags = 'absolute_ref kernel_ref'
  []
[]

[Kernels]
  [heat]
    type = ${AD}Diffusion
    block = 'a c'
    variable = temp
    extra_vector_tags = 'kernel_res total_res'
    absolute_value_vector_tags = 'absolute_ref kernel_ref'
  []
  [heat_ie]
    type = ${AD}HeatConductionTimeDerivative
    block = 'a c'
    variable = temp
    specific_heat = 1
    density_name = 1
    extra_vector_tags = 'kernel_res total_res'
    absolute_value_vector_tags = 'absolute_ref kernel_ref'
  []
  [heat_source]
    type = BodyForce
    block = 'a c'
    variable = temp
    value = 5e3
    extra_vector_tags = 'kernel_res total_res'
    absolute_value_vector_tags = 'absolute_ref kernel_ref'
  []
[]

[Contact]
  [frictional]
    model = coulomb
    # model = frictionless
    formulation = mortar
    primary = a_right
    secondary = c_left
    friction_coefficient = 0.2
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
[]

[MortarGapHeatTransfer]
  [mortar_heat_transfer]
    temperature = temp
    use_displaced_mesh = true
    gap_flux_options = conduction
    gap_conductivity = 1
    boundary = 'a_right c_left'
    primary_boundary = a_right
    secondary_boundary = c_left
    primary_subdomain = frictional_primary_subdomain
    secondary_subdomain = frictional_secondary_subdomain
    gap_geometry_type = CYLINDER
    primary_emissivity = 0
    secondary_emissivity = 0
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
[]

[BCs]
  [no_y_clad]
    type = ${AD}DirichletBC
    variable = disp_y
    boundary = 'bottom'
    value = 0.0
    preset = false
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
  [no_x_clad]
    type = ${AD}DirichletBC
    variable = disp_x
    boundary = 'right'
    value = 0.0
    preset = false
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
  [Pressure]
    [coolantPressure]
      boundary = 'a_right c_left'
      factor = 0.345e6
      use_automatic_differentiation = ${use_ad}
      extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
    []
  []
  [convection]
    type = ConvectiveHeatFluxBC
    variable = temp
    boundary = right
    T_infinity = 298
    heat_transfer_coefficient = 1e-1
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
  [top]
    type = ${AD}DirichletBC
    variable = temp
    boundary = top
    value = 298
    extra_vector_tags = 'constraint_res total_res'
    absolute_value_vector_tags = 'absolute_ref constraint_ref'
  []
[]

[Materials]
  [elasticity_tensor]
    type = ${AD}ComputeIsotropicElasticityTensor
    block = 'a c'
    poissons_ratio = 0.3
    youngs_modulus = 1e10
  []
  [thermal_expansion_a]
    type = ${AD}ComputeThermalExpansionEigenstrain
    thermal_expansion_coeff = 1e-5
    block = 'a'
    temperature = temp
    stress_free_temperature = 298.0
    eigenstrain_name = thermal_strain
  []
  [thermal_expansion_c]
    type = ${AD}ComputeThermalExpansionEigenstrain
    thermal_expansion_coeff = 1e-6
    block = 'c'
    temperature = temp
    stress_free_temperature = 298.0
    eigenstrain_name = thermal_strain
  []
  [stress]
    type = ${AD}ComputeFiniteStrainElasticStress
    block = 'a c'
  []
[]

[Convergence]
  [temp_ref_check]
    type = ReferenceResidualConvergence
    reference_vector = 'absolute_ref'
    converge_on = 'temp'
    nl_rel_tol = 5e-6
    nl_abs_tol = 5e-9
    nl_max_its = 20
    nl_div_tol = -1
    verbose = true
    unscale_the_residual = true
  []
  [disp_ref_check]
    type = ReferenceResidualConvergence
    reference_vector = 'absolute_ref'
    converge_on = 'disp_x disp_y'
    nl_rel_tol = 5e-6
    nl_abs_tol = 5e-9
    nl_max_its = 20
    nl_div_tol = -1
    verbose = true
    unscale_the_residual = true
  []
  [all_ref_conv]
    type = ParsedConvergence

    symbol_names = 'temp_ref_check disp_ref_check'
    symbol_values = 'temp_ref_check disp_ref_check'

    convergence_expression = 'temp_ref_check & disp_ref_check'
    divergence_expression = 'temp_ref_check | disp_ref_check'
  []
[]

[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  nonlinear_convergence = all_ref_conv
  petsc_options = '-snes_ksp_ew -snes_converged_reason -ksp_converged_reason'
  petsc_options_iname = '-pc_type -pc_factor_shift_type -pc_factor_shift_amount'
  petsc_options_value = 'lu NONZERO               1e-25'
  line_search = 'none'
  verbose = true

  l_max_its = 60

  num_steps = 9
  dt = 0.1
[]

[Postprocessors]
  [temp_avg]
    type = ElementAverageValue
    variable = temp
    outputs = console
  []
  [constraint_res_temp]
    type = NodalL2Norm
    variable = constraint_res_temp
    outputs = console
  []
  [constraint_res_disp_x]
    type = NodalL2Norm
    variable = constraint_res_disp_x
    outputs = console
  []
  [constraint_res_disp_y]
    type = NodalL2Norm
    variable = constraint_res_disp_y
    outputs = console
  []
  [kernel_res_temp]
    type = NodalL2Norm
    variable = kernel_res_temp
    outputs = console
  []
  [kernel_res_disp_x]
    type = NodalL2Norm
    variable = kernel_res_disp_x
    outputs = console
  []
  [kernel_res_disp_y]
    type = NodalL2Norm
    variable = kernel_res_disp_y
    outputs = console
  []

  [constraint_ref_temp]
    type = NodalL2Norm
    variable = constraint_ref_temp
    outputs = console
  []
  [constraint_ref_disp_x]
    type = NodalL2Norm
    variable = constraint_ref_disp_x
    outputs = console
  []
  [constraint_ref_disp_y]
    type = NodalL2Norm
    variable = constraint_ref_disp_y
    outputs = console
  []
  [kernel_ref_temp]
    type = NodalL2Norm
    variable = kernel_ref_temp
    outputs = console
  []
  [kernel_ref_disp_x]
    type = NodalL2Norm
    variable = kernel_ref_disp_x
    outputs = console
  []
  [kernel_ref_disp_y]
    type = NodalL2Norm
    variable = kernel_ref_disp_y
    outputs = console
  []

  [absolute_ref_temp]
    type = NodalL2Norm
    variable = absolute_ref_temp
    outputs = console
  []
  [absolute_ref_disp_x]
    type = NodalL2Norm
    variable = absolute_ref_disp_x
    outputs = console
  []
  [absolute_ref_disp_y]
    type = NodalL2Norm
    variable = absolute_ref_disp_y
    outputs = console
  []
  [total_res_temp]
    type = NodalL2Norm
    variable = total_res_temp
    outputs = console
  []
  [total_res_disp_x]
    type = NodalL2Norm
    variable = total_res_disp_x
    outputs = console
  []
  [total_res_disp_y]
    type = NodalL2Norm
    variable = total_res_disp_y
    outputs = console
  []

  [scaled_res_temp]
    type = ParsedPostprocessor
    pp_names = 'total_res_temp'
    expression = 'total_res_temp / ${temp_scaling}'
  []
  [scaled_res_disp_x]
    type = ParsedPostprocessor
    pp_names = 'total_res_disp_x'
    expression = 'total_res_disp_x / ${disp_x_scaling}'
  []
  [total_num_nonlinear_its]
    type = NumNonlinearIterations
  []
[]

[Outputs]
  csv = true
  time_step_interval = 9
[]

[Debug]
  show_var_residual_norms = true
[]

(test/tests/convergence/multi_postprocessor_convergence/multi_postprocessor_convergence.i)

# pp1 converges (< 1e-6) at t=2
# pp2 converges (< 1e-7) at t=3
# Therefore, all converge at t=3, so expected number of dt=1 steps is 3.

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 1
[]

[Functions]
  [pp1_fn]
    type = PiecewiseLinear
    x = '0    1    2    3    4    5'
    y = '1e-6 1e-3 1e-6 1e-7 1e-8 1e-9'
  []
  [pp2_fn]
    type = PiecewiseLinear
    x = '0    1    2    3    4    5'
    y = '1e-8 1e-6 1e-6 1e-8 1e-9 1e-9'
  []
[]

[Postprocessors]
  [pp1]
    type = FunctionValuePostprocessor
    function = pp1_fn
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [pp2]
    type = FunctionValuePostprocessor
    function = pp2_fn
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Convergence]
  [ss_conv_with_descriptions]
    type = MultiPostprocessorConvergence
    postprocessors = 'pp1 pp2'
    descriptions = 'QuantityA QuantityB'
    tolerances = '1e-5 1e-7'
  []
  [ss_conv_without_descriptions]
    type = MultiPostprocessorConvergence
    postprocessors = 'pp1 pp2'
    tolerances = '1e-5 1e-7'
  []
  [ss_conv]
    type = ParsedConvergence
    convergence_expression = 'conv1 & conv2'
    symbol_names = 'conv1 conv2'
    symbol_values = 'ss_conv_with_descriptions ss_conv_without_descriptions'
  []
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Transient
  dt = 1
  num_steps = 5
  steady_state_detection = true
  steady_state_convergence = ss_conv
  verbose = true
[]

[Outputs]
  [out]
    type = CSV
    execute_on = 'FINAL'
  []
[]

(test/tests/time_steppers/iteration_adaptive/adapt_linear_systems.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 50
  ny = 2
  xmax = 5
[]

[Problem]
  linear_sys_names = 'u_sys'
[]

[Variables]
  [u]
    type = MooseLinearVariableFVReal
    solver_sys = 'u_sys'
    initial_condition = 1.0
  []
[]

[LinearFVKernels]
  [time]
    type = LinearFVTimeDerivative
    variable = 'u'
  []
  [diffusion]
    type = LinearFVDiffusion
    variable = u
    diffusion_coeff = 5
  []
  [source]
    type = LinearFVSource
    variable = u
    source_density = 2
  []
[]

[LinearFVBCs]
  [dir]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = u
    boundary = "left right"
    functor = 12
  []
[]

[Executioner]
  type = Transient
  system_names = u_sys
  start_time = 0.0
  end_time = 19
  n_startup_steps = 2
  dtmax = 6.0
  [TimeStepper]
    type = IterationAdaptiveDT
    optimal_iterations = 8
    dt = 1.0
  []
  verbose = true
  linear_convergence = much_logic
[]

[Convergence]
  [force_grow]
    type = IterationCountConvergence
    min_iterations = 0
    max_iterations = 4
    converge_at_max_iterations = true
  []
  [force_shrink]
    type = IterationCountConvergence
    min_iterations = 12
    max_iterations = 13
    converge_at_max_iterations = true
  []
  [much_logic]
    type = ParsedConvergence
    convergence_expression = 'if(time < 5, force_grow, force_shrink)'
    symbol_names = 'time force_grow force_shrink'
    symbol_values = 'time force_grow force_shrink'
  []
[]

[Postprocessors]
  [_dt]
    type = TimestepSize
  []
  [time]
    type = TimePostprocessor
  []
[]

[Outputs]
  csv = true
[]

(test/tests/convergence/parsed_convergence/base.i)

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

[Variables]
  [u]
  []
[]

[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
  []
[]

[Functions]
  [test_fn]
    type = ConstantFunction
    value = 0
  []
[]

[Postprocessors]
  [test_pp]
    type = ConstantPostprocessor
    value = -1e-6
  []
  [num_nl_iterations]
    type = NumNonlinearIterations
    execute_on = 'TIMESTEP_END'
  []
[]

[Convergence]
  [parsed_conv]
    type = ParsedConvergence
    convergence_expression = 'fn | (supplied & abs(pp) < tol)'
    symbol_names = 'supplied pp tol fn'
    symbol_values = 'supplied_conv test_pp 1e-5 test_fn'
  []
[]

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

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

Input Parameters
Input Files