Instructions for Use

Topology check refers to an operation that checks point, line, and surface data based on corresponding topology rules and returns objects that do not comply with the rules. The operator supports the following 7 topological rules: no overlap within a plane, no overlap between faces, faces covered by a surface, no overlap within a line, no overlap between lines, and no duplicate points. |Topology Rules | Illustration | Explanation| | :-------- |:--------| :------| |No duplicate points |! [] (../../img/TopologyValidate0. png) | Duplicate point objects in checkpoint datasets, such as fire stations, schools, and other public facilities, typically exist in the form of point datasets on maps, and can only exist once at the same location. Duplicate point objects will be generated as topology errors in the resulting dataset| |No overlap within the line |! [] (../../img/TopologyValidate2. png) | Check for overlapping line objects in a line dataset, such as city streets. Single or multiple streets can intersect but cannot have the same route. The overlapping parts will be generated as topology errors in the resulting dataset| |There is no overlap between lines |! [] (../../img/TopologyValidate3. png) | Check if there are any overlapping parts of line objects between two line datasets. In transportation route data, highways and railways cannot overlap. The overlapping parts will be generated as topology errors in the resulting dataset| |The noodles are covered in bread |! [] (../../img/TopologyValidate4. png) | Check whether there are face objects in the face dataset that are not included in the reference face dataset. For surface data that belongs to inclusion relationships, such as animal activity areas that must be within the entire study area, this rule can be used to check. The face as a whole that is not included will be generated as a topology error in the resulting dataset| |Cover the surface with a quilt |! [] (../../img/TopologyValidate5. png) | Check whether there are face objects in the face dataset that are not covered by the face of the reference face dataset. This rule is often used for face data nested within a certain rule, such as a province in a region map that must be fully covered by all county boundaries within the province| |No overlap within the plane |! [] (../../img/TopologyValidate6. png) | Check for overlapping face objects in a face dataset. This rule is often used when an area cannot belong to two objects at the same time. As for the administrative division surface, there must be no overlap between adjacent divisions, and the administrative division data must have clear regional definitions for each region| |No overlap between faces |! [] (../../img/TopologyValidate7. png) | Check all overlapping objects in two face datasets. This rule checks all objects in the first face data that overlap with the second face data. If water data is overlaid with dry land data, this rule can be used to check| Distributed topology checking provides two functions: regular [topology checking [/span>] and [DSF topology checking [/span>]. The difference lies in the different input data sources: Topology check: capable of inputting datasets read from various vector data sources, such as SHP, PostGIS, Oracle, etc; DSF topology check can only input datasets read from SuperMap DSF data sources. If DSF is used as a distributed analysis data source, it can improve analysis efficiency. The two data sources that perform analysis need to have the same geographical partition index, and the operator results output the feature dataset.

Parameter Description

The parameters for Topology Check and DSF Topology Check are the same: |Parameter Name | Default Value | Parameter Definition | Parameter Type| |:-----|:----|:-------|:----| |Checked Dataset | | Checked Dataset, supports point, line, and surface, corresponding to topology check rules | FeatureRDD| |Topology Check Rules | | Topology Check Rules, corresponding to the inspected dataset, detailed instructions can be found in the above table | JavaTopologyRule| |The tolerance used for the specified topology error check | | The tolerance used for the specified topology error check. The unit is the same as the dataset for topology error checking. The default value is 0.0. When the tolerance is less than 1.0e-10, if the coordinate system of the dataset is a geographic coordinate system, the node tolerance of 1.0e-7 will be used; when the coordinate system is empty or the projection coordinate system, the node tolerance of 1.0e-2 will be used| Double| |Reference dataset for inspection
(Optional) | | Reference dataset for inspection. If the topology rules used do not require reference to the dataset, there is no need to set | FeatureRDD|