Union (Merge)
Function Description
Union (merge) refers to the function of performing union operations on multiple datasets. For details, please see Overlay Analysis Tools.
Feature Entry
- Toolbox->Vector Analysis->Overlay Analysis->Union (Merge);
- Spatial Analysis Tab->Vector Analysis->Overlay Analysis->Union (Merge)；
Parameter Description
- Source Dataset: Select the source dataset and its corresponding datasource for overlay analysis.
- Save Type: Specifies the property field type to save in overlay analysis results. Default value is "All", which preserves all property fields and Object IDs.
- All: Preserve all property fields and Object IDs;
- Object ID: Preserve only Object IDs;
- Non-system fields: Preserve only non-system fields of geometries (SmUserID field excluded).
- Datasources: Select the datasource to store result datasets.
- Dataset: Specify the name for the result dataset.
- Tolerances: Default tolerance values will be automatically provided based on the datasets involved in the analysis.
After overlay operation, if the distance between two nodes is smaller than this value, they will be merged. The default value equals the fuzzy tolerance of the clipped dataset, which can be set in the Fuzzy field under Tolerances section of the Vector Dataset Tab in Dataset Properties dialog.
If fuzzy tolerance is not set in Dataset Properties, the default tolerance here depends on the dataset's coordinate system. For details, see Tolerance Description.
- Compare Results: When checked, automatically generates comparison diagrams between result data and source data, displayed on the map.
Notes:Before performing overlay analysis, ensure consistent projection for all datasets involved, otherwise the analysis may fail.
Related Topics