PiecewiseConstantFromCSV

Uses data read from CSV to assign values

Description

The PiecewiseConstantFromCSV function is used to load data from a CSV file into a function. The PropertyReadFile user object takes care of reading the CSV file, and the function queries information from it.

It can assume CSV data

  • is sorted by element-id, in which case, when the function is evaluated at a point, it will locate the element containing it then return the value for that element in the CSV file

  • is sorted by node-id, in which case, when the function is evaluated at a point, it will locate the node at that point then return the value for that node in the CSV file

  • is sorted by blocks, in which case, when the function is evaluated at a point, it will locate the element containing it then return the value for that element's block in the CSV file

  • defines an interpolation grid, with the voronoi "read_type", in which case the function will locate the closest point in that interpolation grid, then return the value for that point in the CSV file

For the latter case, the first three columns of the CSV data must define the coordinates of each point forming the interpolation grid. The "column_number" parameter should still match the actual column number in the CSV file, so it likely should be larger than 3 (the number of columns for voronoi centers coordinates).

commentnote

When use data by block or by element, if there is multiple possibilities for the element to choose from, for example at a node, the element with the lowest ID will be used.

commentnote

The "column_number" parameter assumes 0-based indexing of the columns in the CSV file. If you want the values from the leftmost column in the file, you must use a column number of 0.

Example Input Syntax

In this example, we display four options for using CSV data to compute a function over an unstructured mesh:

  • the element Function, using the reader_element user object, assumes the CSV file is sorted by element ID, and returns the value of the element containing each point

  • the node Function, using the reader_node user object, assumes the CSV file is sorted by node ID, and returns the corresponding value at those nodes. Outside of these nodes, the function is currently set to error.

  • the nearest Function, using the reader_nearest user object, finds the closest point defined in the CSV file, and returns the corresponding value

  • the block Function, using the reader_block user object, assumes the data in the CSV file is sorted by block, and returns the value corresponding to the block containing each point

[Functions]
  [element]
    type = PiecewiseConstantFromCSV
    read_prop_user_object = 'reader_element'
    read_type = 'element'
    # 0-based indexing
    column_number = '2'
  []
  [node]
    type = PiecewiseConstantFromCSV
    read_prop_user_object = 'reader_node'
    read_type = 'node'
    # 0-based indexing
    column_number = '2'
  []
  [nearest]
    type = PiecewiseConstantFromCSV
    read_prop_user_object = 'reader_nearest'
    read_type = 'voronoi'
    # 0-based indexing
    column_number = '3'
  []
  [block]
    type = PiecewiseConstantFromCSV
    read_prop_user_object = 'reader_block'
    read_type = 'block'
    # 0-based indexing
    column_number = '3'
  []
[]

[UserObjects]
  [reader_element]
    type = PropertyReadFile
    prop_file_name = 'data_element.csv'
    read_type = 'element'
    nprop = 3 # number of columns in CSV
  []
  [reader_node]
    type = PropertyReadFile
    prop_file_name = 'data_node.csv'
    read_type = 'node'
    nprop = 3 # number of columns in CSV
  []
  [reader_nearest]
    type = PropertyReadFile
    prop_file_name = 'data_nearest.csv'
    read_type = 'voronoi'
    nprop = 4 # number of columns in CSV
    nvoronoi = 3 # number of rows that are considered
  []
  [reader_block]
    type = PropertyReadFile
    prop_file_name = 'data_nearest.csv'
    read_type = 'block'
    nprop = 4 # number of columns in CSV
    nblock = 3 # number of rows that are considered
  []
[]
(moose/test/tests/functions/piecewise_constant_from_csv/piecewise_constant.i)

Other functions which may read data from CSV

These functions read spatial data from CSV, e.g. data that is sorted by location not node, element or block.

Input Parameters

  • column_numberThe column number (0-indexing) for the desired data in the CSV

    C++ Type:unsigned int

    Unit:(no unit assumed)

    Controllable:No

    Description:The column number (0-indexing) for the desired data in the CSV

  • read_prop_user_objectThe PropertyReadFile GeneralUserObject to read element specific property values from file

    C++ Type:UserObjectName

    Unit:(no unit assumed)

    Controllable:No

    Description:The PropertyReadFile GeneralUserObject to read element specific property values from file

  • read_typeOrganization of data in the CSV file: element:by element node: by node voronoi:nearest neighbor / voronoi tesselation structure block:by mesh block

    C++ Type:MooseEnum

    Unit:(no unit assumed)

    Options:element, voronoi, block, node

    Controllable:No

    Description:Organization of data in the CSV file: element:by element node: by node voronoi:nearest neighbor / voronoi tesselation structure block:by mesh block

Required Parameters

  • ghost_layers1

    Default:1

    C++ Type:unsigned short

    Unit:(no unit assumed)

    Controllable:No

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