The fieldExtents function object computes the spatial minimum and maximum extents of an input field.

The extents are derived from the bound box limits after identifying the locations where field values exceed the user-supplied threshold value.


Operand Type Location
input - -
output file dat $FOAM_CASE/postProcessing/<FO>/<time>/<file>
output field - -


Example of the fieldExtents function object by using functions sub-dictionary in system/controlDict file:

    // Mandatory entries (unmodifiable)
    type            fieldExtents;
    libs            (fieldFunctionObjects);

    // Mandatory entries (runtime modifiable)
    fields              (<field1> <field2> ... <fieldN>);
    threshold           0.5;

    // Optional entries (runtime modifiable)
    internalField       true;
    referencePosition   (0 0 0);

    // Optional (inherited) entries
    writePrecision  8;
    writeToFile     true;
    useUserTime     true;
    region          region0;
    enabled         true;
    log             true;
    timeStart       0;
    timeEnd         1000;
    executeControl  timeStep;
    executeInterval 1;
    writeControl    timeStep;
    writeInterval   1;

where the entries mean:

Property Description Type Required Default
type Type name: fieldExtents word yes -
libs Library name: fieldFunctionObjects word yes -
threshold Value to identify extents boundary scalar yes -
fields List of operand fields wordList yes -
internalField Flag to process the internal field bool no true
referencePosition Reference position vector no (0 0 0)
patches List of patches to process wordList no <all patches>

The inherited entries are elaborated in:

Usage by the postProcess utility is not available.

Notes on entries

For non-scalar fields, the magnitude of the field is employed and compared to the value of threshold.

Stored properties

Reduced data

The following data are stored by the function object, and can be used by other function objects:

  • <field-name>_internal_min : bound box minimum for field
  • <field-name>_internal_max : bound box maximum for field

Further information


Source code:



  • Introduced in version v1812