Aggregate nodes and Rollup nodes can apply functions, such as Sum, Average, Max, and others, to the output. The Function Editor provides a way to configure functions assigned to the output schema field
of either type of node.
The function editor consists of three main sections:
Function selector
The function selector allows you to select which function to assign to an output field. All available functions are contained in the function option list. Each function includes a function description.
Parameter selector
The function parameter selector is a table of fields available as argument data sources. Each row of the table represents a schema field from an incoming schema source. Each row includes the "namespaced" schema field name, which includes the name of the source graph node component followed by the schema field name, and the schema field data type.
When the function cursor executes, the selected schema fields provide the argument data for the selected function.
Field Assignment editor
When a function executes, it assigns the results to the associated node schema output field. You can type the field name into the output field text box editor. The function selection determines the field data type (return type of the selected function).
The assignment field editor includes a facets (BFacets) editor. In cases where the selected input fields of a function include different units (BUnit facet data) you need to select the unit type for the output field.
Example 1. Example Facet assignment
As an example, assume you have two schema fields that you wish to use as data arguments for a Max function. The first field values are defined in units of Celsius, while the second field units are defined in units of Fahrenheit.
In order to compare the two values, you must have a common unit type. You must also define the unit type of your result so
that you can correctly interpret the data from the assigned function.
By assigning the unit type to the output field, you provide the common unit type used for comparison by the function at time of cursor execution. You also determine the unit type used for the comparison result, which determines the actual value of the result data.
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