Generates an error surface from a match found inside the GeoStan/zOS handle.
Syntax
05 GDL-GENERATE-ERROR-SURFACE.
10 GDL-GES-HANDLE PIC S9(09) BINARY.
10 GDL-GES-GEOSTAN PIC S9(09) BINARY.
10 GDL-GES-DISTANCE PIC S9(09) BINARY.
10 GDL-GES-POINT PIC S9(09) BINARY.
10 GDL-GES-SURFACE PIC S9(09) BINARY.
*
CALL "GDLGES"
USING GDL-GENERATE-ERROR-SURFACE, GDL-RETURN-CODE.Arguments
GDL-GES-HANDLE
The gdlHandle initialized by GDLINIT (GDL-INIT- HANDLE). Input.
GDL-GES-GEOSTAN
The GsId from the GeoStan/zOS library. This handle must contain a valid GeoStan/zOS match. Input.
GDL-GES-DISTANCE
The distance, in feet, to buffer Address Level and ZIP+4 Level matches. Input.
GDL-GES-POINT
Pointer to a gdlShape that contains the geocode coordinates. Output.
GDL-GES-SURFACE
Pointer to a gdlShape that contains the error surface coordinates. Output.
Return Values
| GDL-OK | Success |
| GDL-ERROR | An internal error occurred |
| GDL-NO-ADDRESSMATCH- FOUND | GeoStan was not used to find a location prior to calling this function |
| GDL-ZIP5-FILE-ERROR | The ZIP5 file is not set or points to an invalid location |
| GDL-ZIP9-FILE-ERROR | The ZIP9 file is not set or points to an invalid location |
Prerequisites
GDLSS and GSFIND (from GeoStan)
Alternates
None.
Notes
After a call to GDLGES, the internal data geocode buffers maintained by the GeoStan/zOS handle are set to NULLs. Because of this, the GeoStan/zOS handle is always invalidated after a call to GDLGES.
Following instances of point or surface arguments of this procedure, you should call GDLSF with the output shape (point and surface) when you are finished using the output shape to release system resources.
The GDLGES procedure provides a worst-case scenario for address location. The geocode error surface (geo-variance region) provides the smallest possible surface that an address can be determined. The GDL/zOS generates the geocode error surfaces.
Based on the GeoStan/zOS Match Code, a buffer is built around a given street segment, ZIP+4, or ZIP+2 that indicates a geo-variance surface that contains the location.
| Match Code | Geo-Variance (Error) Surface |
|---|---|
| Address Level | Buffer street segment |
| Intersection Match | Circular buffer that represents 2X the buffer distance |
| ZIP+4 | Buffer all street segments in ZIP+4 |
| ZIP+2 | Convex Hull around all ZIP+4s that make up a ZIP+2 |
| ZIP Code | The ZIP Code boundary |