MFEMParsedFunction

Summary

Parses scalar function of position, time and scalar problem coefficients (including scalar variables).

Overview

MFEMParsedFunction is responsible for parsing expressions that, in addition to being scalar functions of position and time, can also depend on scalar coefficients, including any scalar variables, postprocessors, material properties or functions specified by the user.

The input parameters are those of ParsedFunction and provide the same flexibility. Note that, in the context of MFEM problems, a scalar variable is a real-valued scalar field, not (necessarily) a constant over the entire domain as elsewhere in MOOSE.

Example Input File Syntax

[Functions<<<{"href": "../../../syntax/Functions/index.html"}>>>]
  [r]
    type = ParsedFunction<<<{"description": "Function created by parsing a string", "href": "../../functions/MooseParsedFunction.html"}>>>
    expression<<<{"description": "The user defined function."}>>> = hypot(x,y)
  []
  [p]
    type = ParsedFunction<<<{"description": "Function created by parsing a string", "href": "../../functions/MooseParsedFunction.html"}>>>
    expression<<<{"description": "The user defined function."}>>> = atan2(y,x)
  []
  [source]
    type = MFEMParsedFunction<<<{"description": "Parses scalar function of position, time and scalar problem coefficients (including scalar variables).", "href": "MFEMParsedFunction.html"}>>>
    expression<<<{"description": "The user defined function."}>>> = v*sin(w*p)
    symbol_names<<<{"description": "Symbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the vals vector."}>>> = 'p w v'
    symbol_values<<<{"description": "Constant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names."}>>> = 'p 4 variable'
  []
  [solution]
    type = MFEMParsedFunction<<<{"description": "Parses scalar function of position, time and scalar problem coefficients (including scalar variables).", "href": "MFEMParsedFunction.html"}>>>
    expression<<<{"description": "The user defined function."}>>> = if(r<=1,-c*sin(w*p)*(r^w-r^2)/(w^2-4),0)
    symbol_names<<<{"description": "Symbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the vals vector."}>>> = 'r p w c'
    symbol_values<<<{"description": "Constant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names."}>>> = 'r p 4 material'
  []
[]

Input Parameters

epsilon0Fuzzy comparison tolerance
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Fuzzy comparison tolerance
expressionThe user defined function.
C++ Type:FunctionExpression
Unit:(no unit assumed)
Controllable:No
Description:The user defined function.
symbol_namesSymbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the vals vector.
C++ Type:std::vector<std::string>
Controllable:No
Description:Symbols (excluding t,x,y,z) that are bound to the values provided by the corresponding items in the vals vector.
symbol_valuesConstant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names.
C++ Type:std::vector<std::string>
Controllable:No
Description:Constant numeric values, postprocessor names, function names, and scalar variables corresponding to the symbols in symbol_names.

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.

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/mfem/functions/parsed_function_source.i)

(test/tests/mfem/functions/parsed_function_source.i)

[Mesh]
  type = MFEMMesh
  file = ../mesh/hinomaru.e
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [variable]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[ICs]
  [ic]
    type = MFEMScalarIC
    variable = variable
    coefficient = material
  []
[]

[BCs]
  [bc]
    type = MFEMScalarDirichletBC
    variable = variable
    boundary = skin
  []
[]

[FunctorMaterials]
  [material]
    type = MFEMGenericFunctorMaterial
    prop_names = material
    prop_values = -100
  []
[]

[Functions]
  [r]
    type = ParsedFunction
    expression = hypot(x,y)
  []
  [p]
    type = ParsedFunction
    expression = atan2(y,x)
  []
  [source]
    type = MFEMParsedFunction
    expression = v*sin(w*p)
    symbol_names = 'p w v'
    symbol_values = 'p 4 variable'
  []
  [solution]
    type = MFEMParsedFunction
    expression = if(r<=1,-c*sin(w*p)*(r^w-r^2)/(w^2-4),0)
    symbol_names = 'r p w c'
    symbol_values = 'r p 4 material'
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = variable
  []
  [source]
    type = MFEMDomainLFKernel
    variable = variable
    coefficient = source
    block = wire
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
[]

[Solver]
  type = MFEMHyprePCG
  preconditioner = boomeramg
  l_tol = 1e-16
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[Postprocessors]
  [error]
    type = MFEML2Error
    variable = variable
    function = solution
  []
[]

[Outputs]
  csv = true
  file_base = OutputData/ParsedFunctionSource
[]

(test/tests/mfem/functions/parsed_function_source.i)

[Mesh]
  type = MFEMMesh
  file = ../mesh/hinomaru.e
[]

[Problem]
  type = MFEMProblem
[]

[FESpaces]
  [H1FESpace]
    type = MFEMScalarFESpace
    fec_type = H1
    fec_order = FIRST
  []
[]

[Variables]
  [variable]
    type = MFEMVariable
    fespace = H1FESpace
  []
[]

[ICs]
  [ic]
    type = MFEMScalarIC
    variable = variable
    coefficient = material
  []
[]

[BCs]
  [bc]
    type = MFEMScalarDirichletBC
    variable = variable
    boundary = skin
  []
[]

[FunctorMaterials]
  [material]
    type = MFEMGenericFunctorMaterial
    prop_names = material
    prop_values = -100
  []
[]

[Functions]
  [r]
    type = ParsedFunction
    expression = hypot(x,y)
  []
  [p]
    type = ParsedFunction
    expression = atan2(y,x)
  []
  [source]
    type = MFEMParsedFunction
    expression = v*sin(w*p)
    symbol_names = 'p w v'
    symbol_values = 'p 4 variable'
  []
  [solution]
    type = MFEMParsedFunction
    expression = if(r<=1,-c*sin(w*p)*(r^w-r^2)/(w^2-4),0)
    symbol_names = 'r p w c'
    symbol_values = 'r p 4 material'
  []
[]

[Kernels]
  [diff]
    type = MFEMDiffusionKernel
    variable = variable
  []
  [source]
    type = MFEMDomainLFKernel
    variable = variable
    coefficient = source
    block = wire
  []
[]

[Preconditioner]
  [boomeramg]
    type = MFEMHypreBoomerAMG
  []
[]

[Solver]
  type = MFEMHyprePCG
  preconditioner = boomeramg
  l_tol = 1e-16
[]

[Executioner]
  type = MFEMSteady
  device = cpu
[]

[Postprocessors]
  [error]
    type = MFEML2Error
    variable = variable
    function = solution
  []
[]

[Outputs]
  csv = true
  file_base = OutputData/ParsedFunctionSource
[]

Summary
Overview
Example Input File Syntax
Input Parameters
Input Files