RelativeDifferencePostprocessor

Description

This post-processor computes the absolute value of the relative difference between 2 post-processor values: where and are the 2 post-processor values. Note that is used as the base for the relative difference. If , then the absolute difference is used instead to prevent division by zero:

Example Syntax

The following example demonstrates how this post-processor is used:

# Tests the RelativeDifferencePostprocessor post-processor, which computes
# the relative difference between 2 post-processor values.

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

[Problem]
  solve = false
[]

[Executioner]
  type = Steady
[]

[Postprocessors]
  [./num_elems]
    # number of elements, equal to 2
    type = NumElems
  [../]
  [./num_nodes]
    # number of nodes, equal to 3
    type = NumNodes
  [../]
  [./zero]
    # zero post-processor value
    type = EmptyPostprocessor
  [../]

  # For the case in this input file, this will be computed as
  #   y = abs((num_nodes - num_elems) / num_elems)
  #   y = abs((3         - 2        ) / 2        ) = 0.5
  # When the command-line modification "Postprocessors/relative_difference/value2=zero" is used,
  #   y = abs(num_nodes - zero)
  #   y = abs(3         - 0   ) = 3
  [./relative_difference]
    type = RelativeDifferencePostprocessor
    value1 = num_nodes
    value2 = num_elems
  [../]
[]

[Outputs]
  [./out]
    type = CSV
    show = relative_difference
  [../]
[]
(test/tests/postprocessors/relative_difference/relative_difference.i)

Input Parameters

  • value1First post-processor

    C++ Type:PostprocessorName

    Controllable:No

    Description:First post-processor

  • value2Second post-processor, base for relative difference

    C++ Type:PostprocessorName

    Controllable:No

    Description:Second post-processor, base for relative difference

Required Parameters

  • execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.

    Default:TIMESTEP_END

    C++ Type:ExecFlagEnum

    Options:FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM, TRANSFER

    Controllable:No

    Description:The list of flag(s) indicating when this object should be executed, the available options include FORWARD, ADJOINT, HOMOGENEOUS_FORWARD, ADJOINT_TIMESTEP_BEGIN, ADJOINT_TIMESTEP_END, NONE, INITIAL, LINEAR, NONLINEAR, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, FINAL, CUSTOM.

  • prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

    C++ Type:MaterialPropertyName

    Controllable:No

    Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.

  • use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Optional Parameters

  • allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

    Default:False

    C++ Type:bool

    Controllable:No

    Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).

  • 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:Yes

    Description:Set the enabled status of the MooseObject.

  • execution_order_group0Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.

    Default:0

    C++ Type:int

    Controllable:No

    Description:Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.

  • force_postauxFalseForces the UserObject to be executed in POSTAUX

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Forces the UserObject to be executed in POSTAUX

  • force_preauxFalseForces the UserObject to be executed in PREAUX

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Forces the UserObject to be executed in PREAUX

  • force_preicFalseForces the UserObject to be executed in PREIC during initial setup

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Forces the UserObject to be executed in PREIC during initial setup

  • outputsVector of output names where you would like to restrict the output of variables(s) associated with this object

    C++ Type:std::vector<OutputName>

    Controllable:No

    Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object

  • use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

    Default:False

    C++ Type:bool

    Controllable:No

    Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

Input Files