SolutionFunction

Function for reading a solution from file.

The solution is a variable in the file but the SolutionFunction makes it available as a function. The SolutionUserObject specified as the solution parameter is used to compute the variable values.

note

The accuracy on the evaluation of this variable in various locations may be diminished by the solution file format. Exodus for example does not store higher order variables accurately.

Example input syntax

In this input file, we load in u_xda_func a reference solution for the problem, previously computed and stored in aux_nonlinear_solution_out_0001.xda, then compare it to the current solution u.

[Functions]
  [./u_xda_func]
    type = SolutionFunction
    solution = xda_u
  [../]
[]

[UserObjects]
  [./xda_u]
    type = SolutionUserObject
    system = nl0
    mesh = aux_nonlinear_solution_out_0001_mesh.xda
    es = aux_nonlinear_solution_out_0001.xda
    system_variables = u
    execute_on = initial
  [../]
[]

[Postprocessors]
  [./unorm]
    type = ElementL2Norm
    variable = u
  [../]
  [./uerror]
    type = ElementL2Error
    variable = u
    function = u_xda_func
  [../]
[]

Input Parameters

solutionThe SolutionUserObject to extract data from.
C++ Type:UserObjectName
Unit:(no unit assumed)
Controllable:No
Description:The SolutionUserObject to extract data from.

Required Parameters

add_factor0Add this value (b) to the solution (x): ax+b, where a is the 'scale_factor'
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Add this value (b) to the solution (x): ax+b, where a is the 'scale_factor'
from_variableThe name of the variable in the file that is to be extracted
C++ Type:std::string
Unit:(no unit assumed)
Controllable:No
Description:The name of the variable in the file that is to be extracted
scale_factor1Scale factor (a) to be applied to the solution (x): ax+b, where b is the 'add_factor'
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scale factor (a) to be applied to the solution (x): ax+b, where b is the 'add_factor'

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
Controllable:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

(moose/test/tests/auxkernels/solution_aux/thread_xda.i)

[Mesh]
  # This test uses SolutionUserObject which doesn't work with ParallelMesh.
  type = GeneratedMesh
  parallel_type = REPLICATED
  dim = 2
  nx = 2
  ny = 2
[]

[Variables]
  [./u]
    order = FIRST
    family = LAGRANGE
  [../]
[]

[Functions]
  [./u_xda_func]
    type = SolutionFunction
    solution = xda_u
  [../]
[]

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

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = 1
    value = 1
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = 2
    value = 2
  [../]
[]

[UserObjects]
  [./xda_u]
    type = SolutionUserObject
    system = nl0
    mesh = aux_nonlinear_solution_out_0001_mesh.xda
    es = aux_nonlinear_solution_out_0001.xda
    system_variables = u
    execute_on = initial
  [../]
[]

[Executioner]
  type = Steady
  solve_type = PJFNK
  nl_rel_tol = 1e-10
[]

[Postprocessors]
  [./unorm]
    type = ElementL2Norm
    variable = u
  [../]
  [./uerror]
    type = ElementL2Error
    variable = u
    function = u_xda_func
  [../]
[]

[Outputs]
  csv = true
[]

Example input syntax
Input Parameters