RealFunctionControl

The RealFunctionControl object is designed to control a "Real" parameter with a function rather than use the value specified in the input file. This object is mainly a demonstration of how to create a Control object and modify a parameter.

Example

Consider a simulation that solves the diffusion equation, where the Laplacian term has a coefficient, but the coefficient is defined as a constant input parameter ("coef"). For some reason, it is desired to control this coefficient and replace the constant value with a function that varies with space and time; this function is defined in the Functions block.

The RealFunctionControl object is designed for this purpose as shown in Listing 1.

Listing 1: Control block demonstrating the use of the RealFunctionControl object.

[Controls]
  [./func_control]
    type = RealFunctionControl
    parameter = '*/*/coef'
    function = 'func_coef'
    execute_on = 'initial timestep_begin'
  [../]
[]

Notice that the "parameter" input parameter is expecting a parameter name which can be defined in various forms.

For a discussion on the naming of objects and parameters see Object and Parameter Names section.

Input Parameters

functionThe function to use for controlling the specified parameter.
C++ Type:FunctionName
Options:
Description:The function to use for controlling the specified parameter.
parameterThe input parameter(s) to control. Specify a single parameter name and all parameters in all objects matching the name will be updated
C++ Type:std::string
Options:
Description:The input parameter(s) to control. Specify a single parameter name and all parameters in all objects matching the name will be updated

Required Parameters

depends_onThe Controls that this control relies upon (i.e. must execute before this one)
C++ Type:std::vector<std::string>
Options:
Description:The Controls that this control relies upon (i.e. must execute before this one)
execute_onINITIAL TIMESTEP_ENDThe list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.
Default:INITIAL TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM, PRE_MULTIAPP_SETUP
Description:The list of flag(s) indicating when this object should be executed, the available options include NONE, INITIAL, LINEAR, NONLINEAR, TIMESTEP_END, TIMESTEP_BEGIN, FINAL, CUSTOM.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
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
Options:
Description:Determines whether this object is calculated using an implicit or explicit form

Advanced Parameters

(moose/test/tests/controls/real_function_control/real_function_control.i)

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

[Variables]
  [./u]
  [../]
[]

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

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

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.1
  dtmin = 0.1
  solve_type = PJFNK
  petsc_options_iname = '-pc_type -pc_hypre_type'
  petsc_options_value = 'hypre boomeramg'
[]

[Outputs]
  csv = true
[]

[Functions]
  [./func_coef]
    type = ParsedFunction
    value = '2*t + 0.1'
  [../]
[]

[Postprocessors]
  [./coef]
    type = RealControlParameterReporter
    parameter = 'Kernels/diff/coef'
  [../]
[]

[Controls]
  [./func_control]
    type = RealFunctionControl
    parameter = '*/*/coef'
    function = 'func_coef'
    execute_on = 'initial timestep_begin'
  [../]
[]

Example
Input Parameters