ArrayFunctionIC

An initial condition that uses a normal function of x, y, z to produce values (and optionally gradients) for a field variable.

All the components of the array variable must be specified simultaneously.

Example input syntax

In this example, initial conditions are set for array variable u and auxiliary array variable v of size 2 using two sinusoid functions.

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u
    function = 'sinx siny'
  []
  [u0ic]
    type = FunctionIC
    variable = u0
    function = sinx
  []
  [u1ic]
    type = FunctionIC
    variable = u1
    function = siny
  []
  [vic]
    type = ArrayFunctionIC
    variable = v
    function = 'sinx siny'
  []
[]

[Functions]
  [sinx]
    type = ParsedFunction
    expression = sin(x)
  []
  [siny]
    type = ParsedFunction
    expression = sin(y)
  []
[]

Input Parameters

functionThe initial condition functions.
C++ Type:std::vector<FunctionName>
Controllable:No
Description:The initial condition functions.
variableThe variable this initial condition is supposed to provide values for.
C++ Type:VariableName
Controllable:No
Description:The variable this initial condition is supposed to provide values for.

Required Parameters

blockThe list of blocks (ids or names) that this object will be applied
C++ Type:std::vector<SubdomainName>
Controllable:No
Description:The list of blocks (ids or names) that this object will be applied
boundaryThe list of boundaries (ids or names) from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Controllable:No
Description:The list of boundaries (ids or names) from the mesh where this object applies
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

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.
ignore_uo_dependencyFalseWhen set to true, a UserObject retrieved by this IC will not be executed before the this IC
Default:False
C++ Type:bool
Controllable:No
Description:When set to true, a UserObject retrieved by this IC will not be executed before the this IC

Advanced Parameters

Input Files

(test/tests/transfers/general_field/nearest_node/regular/sub_array.i)
(test/tests/auxkernels/array_parsed_aux/array_parsed_aux.i)
(test/tests/tag/coupled_array_grad_dot.i)
(test/tests/transfers/multiapp_variable_value_sample_transfer/parent_array_sample.i)
(test/tests/transfers/general_field/shape_evaluation/regular/main_array.i)
(test/tests/transfers/general_field/nearest_node/regular/main_array.i)
(modules/stochastic_tools/test/tests/auxkernels/surrogate_aux/surrogate_array_aux.i)
(test/tests/kernels/array_coupled_time_derivative/test_jacobian.i)
(test/tests/ics/array_function_ic/array_function_ic_test.i)
(test/tests/transfers/multiapp_variable_value_sample_transfer/parent_array_centroid.i)
(test/tests/transfers/general_field/shape_evaluation/regular/sub_array.i)

(test/tests/ics/array_function_ic/array_function_ic_test.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 8
[]

[Problem]
  kernel_coverage_check = false
  solve = false
[]

[Variables]
  [u]
    components = 2
  []
  [u0]
  []
  [u1]
  []
[]

[AuxVariables]
  [v]
    components = 2
  []
[]

[Functions]
  [sinx]
    type = ParsedFunction
    expression = sin(x)
  []
  [siny]
    type = ParsedFunction
    expression = sin(y)
  []
[]

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u
    function = 'sinx siny'
  []
  [u0ic]
    type = FunctionIC
    variable = u0
    function = sinx
  []
  [u1ic]
    type = FunctionIC
    variable = u1
    function = siny
  []
  [vic]
    type = ArrayFunctionIC
    variable = v
    function = 'sinx siny'
  []
[]

[Postprocessors]
  [uint0]
    type = ElementIntegralArrayVariablePostprocessor
    variable = u
    component = 0
  []
  [uint1]
    type = ElementIntegralArrayVariablePostprocessor
    variable = u
    component = 1
  []
  [u0int]
    type = ElementIntegralVariablePostprocessor
    variable = u0
  []
  [u1int]
    type = ElementIntegralVariablePostprocessor
    variable = u1
  []
  [vint0]
    type = ElementIntegralArrayVariablePostprocessor
    variable = v
    component = 0
  []
  [vint1]
    type = ElementIntegralArrayVariablePostprocessor
    variable = v
    component = 1
  []
[]

[Executioner]
  type = Steady
[]

[Outputs]
  exodus = true
[]

(test/tests/transfers/general_field/nearest_node/regular/sub_array.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
  xmax = 0.2
  ymax = 0.2
[]

[AuxVariables]
  [from_main]
    initial_condition = '-1 -1'
    components = 2
  []
  [from_main_elem]
    order = CONSTANT
    family = MONOMIAL
    initial_condition = '-1 -1'
    components = 2
  []
  [to_main]
    [InitialCondition]
      type = ArrayFunctionIC
      function = '3+2*x*x+3*y*y*y 5+2*x*x+3*y*y*y'
    []
    components = 2
  []
  [to_main_elem]
    order = CONSTANT
    family = MONOMIAL
    [InitialCondition]
      type = ArrayFunctionIC
      function = '4+2*x*x+3*y*y*y 6+2*x*x+3*y*y*y'
    []
    components = 2
  []
[]

[Executioner]
  type = Transient
  num_steps = 1
[]

[Problem]
  solve = false
[]

[Outputs]
  [out]
    type = Exodus
    hide = 'to_main to_main_elem'
    overwrite = true
  []
[]

(test/tests/auxkernels/array_parsed_aux/array_parsed_aux.i)

[Mesh]
  [gmg]
    type = GeneratedMeshGenerator
    dim = 1
    nx = 10
  []
[]

[Variables]
  [u]
    components = 2
  []
  [v]
    components = 2
  []
[]

[AuxVariables]
  [const]
    initial_condition = 0.5
  []
  [parsed]
    components = 2
  []
  [sum]
  []
[]

[Functions]
  [cosx]
    type = ParsedFunction
    expression = 'cos(x)'
  []
  [sinx]
    type = ParsedFunction
    expression = 'sin(x)'
  []
  [px]
    type = ParsedFunction
    expression = 'x'
  []
  [mx]
    type = ParsedFunction
    expression = '-x'
  []
[]

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u
    function = 'cosx sinx'
  []
  [vic]
    type = ArrayFunctionIC
    variable = v
    function = 'px mx'
  []
[]

[AuxKernels]
  [parsed_aux]
    type = ArrayParsedAux
    variable = parsed
    expression = '(u^2 + v)*(x - const)*factor'
    coupled_array_variables = 'u v'
    coupled_variables = const
    constant_names = 'factor'
    constant_expressions = '3.14'
    use_xyzt = true
  []
  [sum_aux]
    type = ArrayVarReductionAux
    variable = sum
    array_variable = parsed
  []
[]

[Postprocessors]
  [avg]
    type = ElementAverageValue
    variable = sum
  []
[]

[Outputs]
  exodus = true
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Steady
[]

(test/tests/tag/coupled_array_grad_dot.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 3
[]

[Variables]
  [u]
    order = FIRST
    components = 2
    family = L2_LAGRANGE
  []
  [v]
    order = FIRST
    components = 2
    family = L2_LAGRANGE
  []
[]

[Kernels]
  [u_coupled_time_derivative]
    type = ArrayCoupledTimeDerivative
    variable = u
    v = v
  []
  [u_time_derivative]
    type = ArrayTimeDerivative
    variable = u
  []
  [u_diffusion]
    type = ArrayDiffusion
    variable = u
    diffusion_coefficient = u_dc
  []
  [v_time_derivative]
    type = ArrayTimeDerivative
    variable = v
  []
  [v_diffusion]
    type = ArrayDiffusion
    variable = v
    diffusion_coefficient = v_dc
  []
[]

[ICs]
  [u]
    type = ArrayFunctionIC
    variable = u
    function = '2*(x+1) 3*(x+1)'
  []
  [v]
    type = ArrayFunctionIC
    variable = v
    function = '0.1*(x+1) 0.2*(x+1)'
  []
[]

[Materials]
  [u_dc]
    type = GenericConstantArray
    prop_name = u_dc
    prop_value = '1 1'
  []
  [v_dc]
    type = GenericConstantArray
    prop_name = v_dc
    prop_value = '2 2'
  []
[]


[AuxVariables]
  [u_grad_dot_x]
    order = FIRST
    family = L2_LAGRANGE
    components = 2
  []
[]

[AuxKernels]
  [u_grad_dot_x]
    type = CoupledArrayGradDotAux
    variable = u_grad_dot_x
    v = u
    grad_component = x
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  dt = 0.1
  dtmin = 0.1
  num_steps = 3
  solve_type = 'NEWTON'
[]

[Outputs]
  exodus = true
[]

(test/tests/transfers/multiapp_variable_value_sample_transfer/parent_array_sample.i)

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

[Variables]
  [u_parent]
    components = 2
  []
[]

[AuxVariables]
  [u_sub]
    family = MONOMIAL
    order = CONSTANT
    components = 2
  []
[]

[Functions]
  [u0_fun]
    type = ParsedFunction
    expression = 'x'
  []
  [u1_fun]
    type = ParsedFunction
    expression = 'y'
  []
[]

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u_parent
    function = 'u0_fun u1_fun'
  []
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Steady
[]

[Outputs]
  exodus = true
[]

[MultiApps]
  [sub]
    type = FullSolveMultiApp
    input_files = sub_array_sample.i
    execute_on = timestep_end
    positions = '0.25 0.25 0  0.75 0.25 0  0.25 0.75 0  0.75 0.75 0
                 0.25 0.25 0  0.75 0.25 0  0.25 0.75 0  0.75 0.75 0'
  []
[]

[Transfers]
  [to_transfer]
    type = MultiAppVariableValueSamplePostprocessorTransfer
    to_multi_app = sub
    postprocessor = from_parent
    source_variable = u_parent
    map_array_variable_components_to_child_apps = true
  []
  [from_transfer]
    type = MultiAppVariableValueSamplePostprocessorTransfer
    from_multi_app = sub
    postprocessor = to_parent
    source_variable = u_sub
    map_array_variable_components_to_child_apps = true
  []
[]

(test/tests/transfers/general_field/shape_evaluation/regular/main_array.i)

# Base input for testing transfers. It has the following complexities:
# - more than one subapp
# - transfers both from and to the subapps
# - both nodal and elemental variables
# Tests derived from this input may add complexities through command line arguments

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

[AuxVariables]
  [from_sub]
    initial_condition = '-1 -1'
    components = 2
  []
  [from_sub_elem]
    order = CONSTANT
    family = MONOMIAL
    initial_condition = '-1 -1'
    components = 2
  []
  [to_sub]
    components = 2
    [InitialCondition]
      type = ArrayFunctionIC
      function = '1+2*x*x+3*y*y*y 1.5+2*x*x+3*y*y*y'
    []
  []
  [to_sub_elem]
    components = 2
    order = CONSTANT
    family = MONOMIAL
    [InitialCondition]
      type = ArrayFunctionIC
      function = '2+2*x*x+3*y*y*y 3+2*x*x+3*y*y*y'
    []
  []
[]

[Executioner]
  type = Steady
[]

[Problem]
  solve = false
[]

[Outputs]
  [out]
    type = Exodus
    hide = 'to_sub to_sub_elem'
    overwrite = true
  []
[]

[MultiApps]
  [sub]
    # 1 on corner, one in the center and one close to a corner
    positions = '0 0 0 0.4 0.4 0 0.7 0.1 0'
    type = FullSolveMultiApp
    app_type = MooseTestApp
    input_files = sub_array.i
    output_in_position = true
  []
[]

[Transfers]
  [to_sub]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    to_multi_app = sub
    source_variable = 'to_sub to_sub'
    source_variable_components = '1 0'
    variable = 'from_main from_main'
    target_variable_components = '0 1'
    extrapolation_constant = -1
  []

  [to_sub_elem]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    to_multi_app = sub
    source_variable = 'to_sub_elem to_sub_elem'
    source_variable_components = '1 0'
    variable = 'from_main_elem from_main_elem'
    target_variable_components = '0 1'
    extrapolation_constant = -1
  []

  [from_sub]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    from_multi_app = sub
    source_variable = 'to_main to_main'
    source_variable_components = '1 0'
    variable = 'from_sub from_sub'
    target_variable_components = '0 1'
    extrapolation_constant = -1
  []

  [from_sub_elem]
    type = MultiAppGeneralFieldShapeEvaluationTransfer
    from_multi_app = sub
    source_variable = 'to_main_elem to_main_elem'
    source_variable_components = '1 0'
    variable = 'from_sub_elem from_sub_elem'
    target_variable_components = '0 1'
    extrapolation_constant = -1
  []
[]

(test/tests/transfers/general_field/nearest_node/regular/main_array.i)

# Base input for testing transfers. It has the following complexities:
# - more than one subapp
# - transfers both from and to the subapps
# - both nodal and elemental variables
# Tests derived from this input may add complexities through command line arguments

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

[AuxVariables]
  [from_sub]
    initial_condition = '-1 -1'
    components = 2
  []
  [from_sub_elem]
    order = CONSTANT
    family = MONOMIAL
    initial_condition = '-1 -1'
    components = 2
  []
  [to_sub]
    components = 2
    [InitialCondition]
      type = ArrayFunctionIC
      function = '1+2*x*x+3*y*y*y 1.5+2*x*x+3*y*y*y'
    []
  []
  [to_sub_elem]
    components = 2
    order = CONSTANT
    family = MONOMIAL
    [InitialCondition]
      type = ArrayFunctionIC
      function = '2+2*x*x+3*y*y*y 3+2*x*x+3*y*y*y'
    []
  []
[]

[Executioner]
  type = Steady
[]

[Problem]
  solve = false
[]

[Outputs]
  [out]
    type = Exodus
    hide = 'to_sub to_sub_elem'
    overwrite = true
  []
[]

[MultiApps]
  [sub]
    # 1 on corner, one in the center and one close to a corner
    # The offsets are to avoid equidistant points
    positions = '0.000001 0 0 0.4111 0.4112 0 0.6999 0.099 0'
    type = FullSolveMultiApp
    app_type = MooseTestApp
    input_files = sub_array.i
    output_in_position = true
  []
[]

[Transfers]
  [to_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = sub
    source_variable = 'to_sub to_sub'
    source_variable_components = '1 0'
    variable = 'from_main from_main'
    target_variable_components = '0 1'
    source_type = 'nodes nodes'
  []

  [to_sub_elem]
    type = MultiAppGeneralFieldNearestLocationTransfer
    to_multi_app = sub
    source_variable = 'to_sub_elem to_sub_elem'
    source_variable_components = '1 0'
    variable = 'from_main_elem from_main_elem'
    target_variable_components = '0 1'
    source_type = 'centroids centroids'
  []

  [from_sub]
    type = MultiAppGeneralFieldNearestLocationTransfer
    from_multi_app = sub
    source_variable = 'to_main to_main'
    source_variable_components = '1 0'
    variable = 'from_sub from_sub'
    target_variable_components = '0 1'
    source_type = 'nodes nodes'
  []

  [from_sub_elem]
    type = MultiAppGeneralFieldNearestLocationTransfer
    from_multi_app = sub
    source_variable = 'to_main_elem to_main_elem'
    source_variable_components = '1 0'
    variable = 'from_sub_elem from_sub_elem'
    target_variable_components = '0 1'
    source_type = 'centroids centroids'
  []
[]

(modules/stochastic_tools/test/tests/auxkernels/surrogate_aux/surrogate_array_aux.i)

[Mesh]
  [gmg]
    type = GeneratedMeshGenerator
    dim = 3
    nx = 10
    ny = 10
    nz = 10
  []
[]

[Surrogates]
  [surrogate]
    type = PolynomialRegressionSurrogate
    filename = surrogate_trainer_poly_regression.rd
  []
[]

[AuxVariables]
  [u]
    family = MONOMIAL
    order = CONSTANT
    components = 2
  []
  [u0]
    family = MONOMIAL
    order = CONSTANT
  []
  [u1]
    family = MONOMIAL
    order = CONSTANT
  []
  [array_var]
    family = MONOMIAL
    order = CONSTANT
    components = 2
  []
  [var]
    family = MONOMIAL
    order = CONSTANT
  []
  [reference]
    family = MONOMIAL
    order = CONSTANT
  []
[]

[ICs]
  [array_var_ic]
    type = ArrayFunctionIC
    variable = array_var
    function = 'funx funmx'
  []
  [var_ic]
    type = FunctionIC
    variable = var
    function = funy
  []
[]

[Functions]
  [funx]
    type = ParsedFunction
    expression = 'x'
  []
  [funmx]
    type = ParsedFunction
    expression = '-x'
  []
  [funy]
    type = ParsedFunction
    expression = 'y'
  []
  [funz]
    type = ParsedFunction
    expression = 'z'
  []
  [funt]
    type = ParsedFunction
    expression = 't'
  []

  [reference0]
    type = ParsedFunction
    expression = '1 +   x +   y +   z +   t +
                      x*x + x*y + x*z + x*t +
                            y*y + y*z + y*t +
                                  z*z + z*t +
                                        t*t'
  []
  [reference1]
    type = ParsedFunction
    expression = '1 -   x +   y +   z +   t +
                      x*x - x*y - x*z - x*t +
                            y*y + y*z + y*t +
                                  z*z + z*t +
                                        t*t'
  []
[]

[Postprocessors]
  [pp]
    type = FunctionValuePostprocessor
    function = funt
    point = '0 0 0'
    execute_on = 'INITIAL TIMESTEP_BEGIN'
  []
[]

[AuxKernels]
  [u_aux]
    type = SurrogateModelArrayAuxKernel
    variable = u
    model = surrogate
    parameters = 'array_var var funz pp'
    scalar_parameters = 'funz pp'
    coupled_variables = 'var'
    coupled_array_variables = 'array_var'
    execute_on = 'INITIAL TIMESTEP_END'
  []

  [u0_aux]
    type = ArrayVariableComponent
    variable = u0
    array_variable = u
    component = 0
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [u1_aux]
    type = ArrayVariableComponent
    variable = u1
    array_variable = u
    component = 1
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Postprocessors]
  [diff0]
    type = ElementL2Error
    variable = u0
    function = reference0
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [diff1]
    type = ElementL2Error
    variable = u1
    function = reference1
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Transient
  dt = 0.1
  num_steps = 10
[]

[UserObjects]
  [terminator]
    type = Terminator
    expression = '(diff0 + diff1) > 1e-8'
    error_level = ERROR
  []
[]

(test/tests/kernels/array_coupled_time_derivative/test_jacobian.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 3
[]

[Variables]
  [u]
    components = 2
  []
  [v]
    components = 2
  []
[]

[Kernels]
  [u_coupled_time_derivative]
    type = ArrayCoupledTimeDerivative
    variable = u
    v = v
  []
  [u_time_derivative]
    type = ArrayTimeDerivative
    variable = u
  []
  [u_diffusion]
    type = ArrayDiffusion
    variable = u
    diffusion_coefficient = u_dc
  []
  [v_time_derivative]
    type = ArrayTimeDerivative
    variable = v
  []
  [v_diffusion]
    type = ArrayDiffusion
    variable = v
    diffusion_coefficient = v_dc
  []
[]

[ICs]
  [u]
    type = ArrayFunctionIC
    variable = u
    function = '2*(x+1) 3*(x+1)'
  []
  [v]
    type = ArrayFunctionIC
    variable = v
    function = '0.1*(x+1) 0.2*(x+1)'
  []
[]

[Materials]
  [u_dc]
    type = GenericConstantArray
    prop_name = u_dc
    prop_value = '1 1'
  []
  [v_dc]
    type = GenericConstantArray
    prop_name = v_dc
    prop_value = '2 2'
  []
[]

[Preconditioning]
  [smp]
    type = SMP
    full = true
  []
[]

[Executioner]
  type = Transient
  dt = 0.1
  dtmin = 0.1
  num_steps = 3
  solve_type = 'NEWTON'
  petsc_options = '-snes_test_jacobian -snes_test_jacobian_view'
  petsc_options_iname = '-pc_type'
  petsc_options_value = 'lu'
[]

[Outputs]
  exodus = true
[]

(test/tests/ics/array_function_ic/array_function_ic_test.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 8
[]

[Problem]
  kernel_coverage_check = false
  solve = false
[]

[Variables]
  [u]
    components = 2
  []
  [u0]
  []
  [u1]
  []
[]

[AuxVariables]
  [v]
    components = 2
  []
[]

[Functions]
  [sinx]
    type = ParsedFunction
    expression = sin(x)
  []
  [siny]
    type = ParsedFunction
    expression = sin(y)
  []
[]

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u
    function = 'sinx siny'
  []
  [u0ic]
    type = FunctionIC
    variable = u0
    function = sinx
  []
  [u1ic]
    type = FunctionIC
    variable = u1
    function = siny
  []
  [vic]
    type = ArrayFunctionIC
    variable = v
    function = 'sinx siny'
  []
[]

[Postprocessors]
  [uint0]
    type = ElementIntegralArrayVariablePostprocessor
    variable = u
    component = 0
  []
  [uint1]
    type = ElementIntegralArrayVariablePostprocessor
    variable = u
    component = 1
  []
  [u0int]
    type = ElementIntegralVariablePostprocessor
    variable = u0
  []
  [u1int]
    type = ElementIntegralVariablePostprocessor
    variable = u1
  []
  [vint0]
    type = ElementIntegralArrayVariablePostprocessor
    variable = v
    component = 0
  []
  [vint1]
    type = ElementIntegralArrayVariablePostprocessor
    variable = v
    component = 1
  []
[]

[Executioner]
  type = Steady
[]

[Outputs]
  exodus = true
[]

(test/tests/transfers/multiapp_variable_value_sample_transfer/parent_array_centroid.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 4
  ny = 4
[]

[Variables]
  [u_parent]
    components = 2
  []
[]

[AuxVariables]
  [u_sub]
    family = MONOMIAL
    order = CONSTANT
    components = 2
  []
[]

[Functions]
  [u0_fun]
    type = ParsedFunction
    expression = 'x'
  []
  [u1_fun]
    type = ParsedFunction
    expression = 'y'
  []
[]

[ICs]
  [uic]
    type = ArrayFunctionIC
    variable = u_parent
    function = 'u0_fun u1_fun'
  []
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Steady
[]

[Outputs]
  exodus = true
[]

[Positions]
  [centroid]
    type = ElementCentroidPositions
  []
[]

[MultiApps]
  [sub]
    type = FullSolveMultiApp
    input_files = sub_array_sample.i
    execute_on = timestep_end
    positions_objects = 'centroid centroid'
  []
[]

[Transfers]
  [to_transfer]
    type = MultiAppVariableValueSamplePostprocessorTransfer
    to_multi_app = sub
    postprocessor = from_parent
    source_variable = u_parent
    map_array_variable_components_to_child_apps = true
  []
  [from_transfer]
    type = MultiAppVariableValueSamplePostprocessorTransfer
    from_multi_app = sub
    postprocessor = to_parent
    source_variable = u_sub
    map_array_variable_components_to_child_apps = true
  []
[]

(test/tests/transfers/general_field/shape_evaluation/regular/sub_array.i)

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
  xmax = 0.2
  ymax = 0.2
[]

[AuxVariables]
  [from_main]
    initial_condition = '-1 -1'
    components = 2
  []
  [from_main_elem]
    order = CONSTANT
    family = MONOMIAL
    initial_condition = '-1 -1'
    components = 2
  []
  [to_main]
    [InitialCondition]
      type = ArrayFunctionIC
      function = '3+2*x*x+3*y*y*y 5+2*x*x+3*y*y*y'
    []
    components = 2
  []
  [to_main_elem]
    order = CONSTANT
    family = MONOMIAL
    [InitialCondition]
      type = ArrayFunctionIC
      function = '4+2*x*x+3*y*y*y 6+2*x*x+3*y*y*y'
    []
    components = 2
  []
[]

[Executioner]
  type = Transient
  num_steps = 1
[]

[Problem]
  solve = false
[]

[Outputs]
  [out]
    type = Exodus
    hide = 'to_main to_main_elem'
    overwrite = true
  []
[]

Example input syntax
Input Parameters
Input Files