5.10.11. Geometry Info

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5.10.11. Geometry Info

 

Icon: clip1512

 

Function: GeometryInfo

 

Property window:

 

clip1511

 

Short description:

 

Extract information from Geometries

 

Long Description:

 

The Extracted informations are:

 

GeometryType: it can be: POLYGON,MULTIPOLYGON,POINT, MULTIPOINT,etc.
 

NPoints: Number of points inside the geometry
 

IsValid: 0 or 1
 

NRings: Number of Rings:
 
clip1514

NumGeometries: The Number of geometries inside a MULTI-geometry: For example: The number of POLYGON inside a MULTIPOLYGON geometry
 

SRID: see previous section 5.10.10. for more details on SRID
 

Dimension: 0 for POINT, 1 for LINE, 2 for POLYGON
 

NDims: 2 (when you have Lattitude and Longitude) or 3 (when you have Lattitude, Longitude and Elevation)
 

Is3D: when nDims=3
 

IsEmpty: 0 or 1
 

IsSimple: 0 or 1

 

 
If you check the “detailed info” checkbox, you also get:

 

Area: The area is usually expressed in m² (i.e. divide by 1.000.000 to get it in Km²). In particular, for the SRID 4326, you also directly get the area in m² (personnaly, I expected  the area in degree² for the SRID 4326 but it’s in m². Cool!).
 

Perimeter: The Perimeter is usually expressed in m (this is also true for the SRID 4326 !).
 

Centroid: the POINT at the center of the geometry (in WKT format). It might be outside the POLYGON if the geometry as a “U” shape.
 

Envelope: the minimum bounding rectangle (MBR) around the geometry  (in WKT format)
 

GeoHash: the geohash of the POINT (null if it’s not a POINT)
 

CoordDimension: most of the time: “XY”, sometime: “XYZ”

 

 
To remind you, a .shp file can only contain 1 type of geometry (e.g. it cannot contains both the POLYGON and the MULTIPOLYGON geometry type) and 1 unique SRID. Using the clip1513 geometryInfo action is usefull to see if you can export your Anatella table to a .shp file: if you see several different geometry types or multiple different SRID, then the exportation will fail (this is the most common source of error when exporting to a .shp file).