Setting geospatial options for streams

Any geospatial field, whether it is a shape, coordinate, or single axis value (such as x or y, or latitude and longitude) has an associated coordinate system. This coordinate system sets attributes such as the origin point (0,0) and the units associated with the values.

There are a number of coordinate systems and there are two types: Geographic and Projected. All of the spatial functions in SPSS® Modeler can only be used with a Projected coordinate system.

Due to the nature of coordinate systems, merging or appending data from two separate geospatial data sources requires that the sources use the same coordinate system. Because of this you must specify a coordinate setting for any geospatial data used in the stream.

Data is automatically reprojected to use the chosen stream coordinate system in the following situations:

• For spatial functions (such as area, closeto, within), the parameter passed to the function is automatically reprojected; however, the original row data is left unchanged.
• When using either the build or scoring (nugget) nodes in Spatio-Temporal Prediction (STP), the location field is automatically reprojected. When scoring, the location that comes out of the nugget is the original location.
• When using the Map Visualization node.

Stream coordinate system. Only available if you select the check box. Click Change to display a list of available Projected Coordinate Systems and select the one you want to use for the current stream.

Save As Default. The coordinate system you select only applies to the current stream. To select the system as the default for all streams, click this button.