histogram

Description

The histogram function object computes the volume-weighted histogram of an input volScalarField.

Operands

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

The set written contains two columns, the first the volume averaged values, the second the raw bin count.

Usage

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

histogram1
{
    // Mandatory entries (unmodifiable)
    type            histogram;
    libs            (fieldFunctionObjects);

    // Mandatory (inherited) entries (runtime modifiable)
    field       p;
    nBins       100;
    setFormat   gnuplot;

    // Optional entries (runtime modifiable)
    max         5;
    min        -5;

    // 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: histogram	word	yes	-
libs	Library name: fieldFunctionObjects	word	yes	-
field	Name of operand field	word	yes	-
nBins	Number of histogram bins	label	yes	-
setFormat	Output format	word	yes	-
max	Maximum value sampled	scalar	no	fieldMax
min	minimum value sampled	scalar	no	0.0

The inherited entries are elaborated in:

• functionObject
• writeFile

Usage by the postProcess utility is not available.

Notes on entries

If max is not provided it will use the field's min and max as the bin extremes. If max is provided but not min, it will use 0.

Further information

Tutorial:

• cavity

Source code:

• histogram

API:

• Foam::functionObjects::histogram

History: Introduced in version v1606+