Aggregator

If you do not select Group By attributes, then all features fall into the same group.

When you select Group By attributes, this transformer will aggregate the geometries of the input features, based on the selection in the Group By parameter. Each group of features that have the same values for the Group By attributes will be processed independently of other groups.

If Input is Ordered by Group is set to Yes, the transformer will output all the aggregates it has accumulated every time the values of the Group By attributes change from one feature to the next.

Assemble One Level: combines all features within a group into a single heterogeneous collection, homogeneous collection, or multiple geometry.

Assemble Hierarchy: reconstructs the hierarchical geometries defined by the input features. In this mode, a single group can output multiple heterogeneous collections, homogeneous collections, and/or multiple geometries. Input features should define one or more hierarchical geometries. Remnants of the hierarchy reconstruction process are considered parts of corrupt aggregates and are therefore output via the AGGREGATE output port.

If a Count Attribute is entered, then an attribute with this name will be added to each output aggregate, containing the number of features that were combined to form the aggregate.

If Keep Input Attributes is set to Yes, the attributes from the original features will be merged onto the output AGGREGATE features.

If a List Name is specified, then all attributes of an input feature will be stored as part of a list attribute entry in the output AGGREGATE feature.

Attributes can be concatenated so that the resulting AGGREGATE feature preserves multiple source attribute values under the same attribute name. For example, if input feature 1 has an “id” attribute of 1 and input feature 2 has an “id” attribute of 2, specifying “id” for this parameter together with a separate character of “,” will cause the output AGGREGATE feature to have an “id” with value “1, 2”.

The Separator Character is used to separate elements within an attribute value string. For example, if features with attribute values of “River Rd”, “Marine Dr” and “HWY 1” for the attribute named “Road Name” respectively, and the Separator Character is “, ” (a comma followed by a space) on the output aggregate feature, the attribute “Road Name” will contain “River Rd, Marine Dr, HWY 1” as a value.

The separator character can be expressed as a regular character but it can also contain special characters beginning with a backslash ("\"), as specified in the following table.

If the sequence is not listed in the table, the backslash character is ignored. (For example, entering lan\es will be interpreted as lanes.) If no separator character is supplied, attributes will be concatenated without a separator.

Sequence	Description
\a	Audible alert (bell) (0x07)
\b	Backspace (0x08)
\f	Form feed (0x0c)
\n	Newline (0x0a)
\r	Carriage return (0x0d)
\t	Tab (0x09)
\v	Vertical tab (0x0b)
\\	Backslash (Note: A single backslash entered at the end of a value will be converted to an escaped backslash.)

Any attributes specified in this field will undergo statistical accumulation.

For example, if two input polygons have an attribute “salary” set to 30000 and 50000, then summing them would result in a “salary” of 80000 on the aggregate output.

Any attributes specified in this field will undergo statistical accumulation.

For example, if two input polygons have an attribute “salary” set to 30000 and 50000, then averaging them would result in a “salary” of 40000 on the aggregate output.

Any attributes specified in this field will undergo statistical accumulation.

For example, if two input polygons have an attribute “salary” set to 30000 and 50000, and the second polygon was 3 times larger than the first polygon, then the weighted average would be 45000.

Attributes to Average, Weighted by Area may produce non-numeric results if some input features have zero, or no area.

Heterogeneous Collection: the output geometry will be an IFMEAggregate.

Homogeneous Collection (If Possible): if the output geometry can be made into a homogeneous collection without changing the geometry type of any of its parts, then this option will perform the conversion.

Multiple Geometry: combines input features into a Multiple Geometry.

If Geometry Name Attribute is specified, each incoming feature will store the value of this attribute as the name of the geometry it owns. This way, as the input geometries are combined to form the output AGGREGATE feature, we will have transferred the geometry names onto the output features.

In Assemble Hierarchy mode, the user may reconstruct hierarchical geometries either using ID and Parent ID, ID and Child ID, or all three sets of ID information. If a hierarchical geometry were to be represented as a tree, then each tree node would have a unique ID. Each node would refer to its parent by Parent ID and its children by child IDs.

The attribute that uniquely identifies each input node feature.

The attribute that identifies a node feature’s parent node.

The list attribute that identifies all child nodes of a node.

If set to Yes, then attributes on an input feature will be stored as traits on the geometry owned by the feature. This way as geometries are combined to form aggregates, the input attribute information is preserved.

If set to No, then no input attributes are saved, except the input attributes of the root node feature.

IDs are used to reconstruct hierarchical geometries and may be removed after the reconstruction. Specify Yes to keep these IDs as traits. Specify No to remove these IDs.