derivenode properties

Last updated: Feb 12, 2025

Derive node icon The Derive node modifies data values or creates new fields from one or more existing fields. It creates fields of type formula, flag, nominal, state, count, and conditional.

Example 1

# Create and configure a Flag Derive field node
node = stream.create("derive", "My node")
node.setPropertyValue("new_name", "DrugX_Flag")
node.setPropertyValue("result_type", "Flag")
node.setPropertyValue("flag_true", "1")
node.setPropertyValue("flag_false", "0")
node.setPropertyValue("flag_expr", "'Drug' == \"drugX\"")

# Create and configure a Conditional Derive field node
node = stream.create("derive", "My node")
node.setPropertyValue("result_type", "Conditional")
node.setPropertyValue("cond_if_cond", "@OFFSET(\"Age\", 1) = \"Age\"")
node.setPropertyValue("cond_then_expr", "(@OFFSET(\"Age\", 1) = \"Age\" >< @INDEX")
node.setPropertyValue("cond_else_expr", "\"Age\"")

Example 2

This script assumes that there are two numeric columns called XPos and YPos that represent the X and Y coordinates of a point (for example, where an event took place). The script creates a Derive node that computes a geospatial column from the X and Y coordinates representing that point in a specific coordinate system:

stream = modeler.script.stream()
# Other stream configuration code
node = stream.createAt("derive", "Location", 192, 96)
node.setPropertyValue("new_name", "Location")
node.setPropertyValue("formula_expr", "['XPos', 'YPos']")
node.setPropertyValue("formula_type", "Geospatial")
# Now we have set the general measurement type, define the
# specifics of the geospatial object
node.setPropertyValue("geo_type", "Point")
node.setPropertyValue("has_coordinate_system", True)
node.setPropertyValue("coordinate_system", "ETRS_1989_EPSG_Arctic_zone_5-47")

Table 1. derivenode properties
`derivenode` properties	Data type	Property description
`new_name`	string	Name of new field.
`mode`	`Single` `Multiple`	Specifies single or multiple fields.
`fields`	list	Used in Multiple mode only to select multiple fields.
`name_extension`	string	Specifies the extension for the new field name(s).
`add_as`	`Suffix` `Prefix`	Adds the extension as a prefix (at the beginning) or as a suffix (at the end) of the field name.
`result_type`	`Formula` `Flag` `Set` `State` `Count` `Conditional`	The six types of new fields that you can create.
`formula_expr`	string	Expression for calculating a new field value in a Derive node.
`flag_expr`	string
`flag_true`	string
`flag_false`	string
`set_default`	string
`set_value_cond`	string	Structured to supply the condition associated with a given value.
`state_on_val`	string	Specifies the value for the new field when the On condition is met.
`state_off_val`	string	Specifies the value for the new field when the Off condition is met.
`state_on_expression`	string
`state_off_expression`	string
`state_initial`	`On` `Off`	Assigns each record of the new field an initial value of `On` or `Off`. This value can change as each condition is met.
`count_initial_val`	string
`count_inc_condition`	string
`count_inc_expression`	string
`count_reset_condition`	string
`cond_if_cond`	string
`cond_then_expr`	string
`cond_else_expr`	string
`formula_measure_type`	`Range / MeasureType.RANGE` `Discrete / MeasureType.DISCRETE` `Flag / MeasureType.FLAG` `Set / MeasureType.SET` `OrderedSet / MeasureType.ORDERED_SET` `Typeless / MeasureType.TYPELESS` `Collection / MeasureType.COLLECTION` `Geospatial / MeasureType.GEOSPATIAL`	This property can be used to define the measurement associated with the derived field. The setter function can be passed either a string or one of the `MeasureType` values. The getter will always return on the `MeasureType` values.
`collection_measure`	`Range / MeasureType.RANGE` `Flag / MeasureType.FLAG` `Set / MeasureType.SET` `OrderedSet / MeasureType.ORDERED_SET` `Typeless / MeasureType.TYPELESS`	For collection fields (lists with a depth of 0), this property defines the measurement type associated with the underlying values.
`geo_type`	`Point` `MultiPoint` `LineString` `MultiLineString` `Polygon` `MultiPolygon`	For geospatial fields, this property defines the type of geospatial object represented by this field. This should be consistent with the list depth of the values
`has_coordinate_system`	boolean	For geospatial fields, this property defines whether this field has a coordinate system
`coordinate_system`	string	For geospatial fields, this property defines the coordinate system for this field

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