Aggregate Features/Records:

Selecting aggregation geometry type and function(s)

 

 

For the fields not involved in aggregation various aggregation functions can be determined.

 

 

A name of a resulting field, suggested by default, consists of a prefix and a source field name. The type of a resulting field is the same that the type of a source field.  

 

The aggregation functions are following:

• First – the first element in a group

Prefix: first_

Records in a group are sorted by ObjectID if there is such field in the data source.

• Last – the last element in a group

Prefix: last_

Records in a group are sorted by ObjectID if there is such field in the data source.

• Count – number of records in a group, where this value of this field is not NULL

Prefix: count_

• Sum – sum of elements in a group;

Prefix: sum_

This function is applicable for numeric fields only

• Average – average value of elements in a group

Prefix: avg_

This function is applicable for numeric fields only

• Minimum – the minimum element value in a group; prefix: min_

• Maximum – the maximum element value in a group; prefix: max_

• Variance – variance of elements in a group;

Prefix: var_

Type of resulting field: double

This function is applicable for numeric fields only

• Standard deviation – standard deviation of elements in a group

Prefix: dev_;

Type of resulting field: double

This function is applicable for numeric fields only

 

Following "Geometry aggregation" types can be set for resulting data:

 

• "Multipart" - this is the default value is set, it means that aggregated features will be grouped into multipart features.

• "None" - resulting data will have no geometry.

• "Convex Hull" - a convex hull will be built for resulting data. If this value is selected, the "Buffer Size" field is activated. To set the Buffer Size for a hull, please, input a value not equal to null, into the "Buffer Size" field. Null is the default value of the Buffer Size. Null Buffer Size means unchanged hull size. The Buffer Size units are the units of a selected layer. If the "Buffer Size" value is positive (more than null), the hull will exceed its normal size for the amount, indicated in the Buffer Size field. If the "Buffer Size" value is negative (more than null), the hull will be less than its normal size for the amount, indicated in the Buffer Size field. The Buffer Size may have not only integral values but also decimal fraction values.

• "Convex Hull detailed" - a convex hull with more detailed shape will be built.

• "Polyline" - input point features will be aggregated and grouped into polylines.

• "Polygon" - input point or polyline features will be aggregated and grouped into polygons.

 

---