Create Polygon Geometry - 23.1

Spectrum Dataflow Designer Guide

Version
23.1
Language
English
Product name
Spectrum Technology Platform
Title
Spectrum Dataflow Designer Guide
First publish date
2007
Last updated
2024-05-09
Published on
2024-05-09T23:01:03.226155

Converts a specified set of line segments to a polygon geometry. The input to the stage is a list or a list of lists. If given a single list, then a multipolygon with a single polygon with no holes will be created. If more than one list is specified, then each list is considered a ring and an algorithm is used to determine which list is an inner ring and which is an outer ring. The result can range from a single polygon with a single hole to several multipolygons with some having holes and some not.

Example:

Table 1. Create Polygon Options
Option Name Description
Coordinate system

This field specifies the coordinate system to use for the polygon.

To change the default coordinate system, clear the default value then start typing the name of a coordinate system or an EPSG code to see a drop-down list of systems that begin with or contain those characters (the list appears after you have entered three alphanumeric characters). You can also click the browse button to open the Select Coordinate System dialog and select one from the list. Regardless of which coordinate system you select, the descriptive name will appear in the field and the respective EPSG code is saved for the stage.

For more information on EPSG codes, see www.spatialreference.org. To retrieve a list of supported codespaces for EPSG, you can submit the SOAP request List Supported CoordSys by Code Space from the Geometry Service Demo page at http://<server>:<port>/Spatial/GeometryService/DemoPage.html.

Line segments The field containing a set of closed line segments to convert to a polygon geometry. You create this field using an Aggregator stage in Enterprise Designer to construct a list of polygons that gets passed to Spatial Calculator. This field must be a List of ListFieldType with subfields as follows:
List of ListFieldType
	Latitude
	Longitude

or

List of ListFieldType
	Polygon
		List of ListFieldType
			Latitude
			Longitude

To create a Line Segments field for polygons without holes, see Using Aggregator to Create a Segment Points Field for a similar procedure.

If your data includes polygons with holes (inner and outer polygons), use a custom transformer to create the Line Segments field. See Using Transformer to Create a Line Segments Field

Geometry field The name of the field that you want to contain the polygon returned by Spatial Calculator; the default is Geometry.