Class SpatialCentroid
- Namespace
- YndigoBlue.Velocity.Functions
- Assembly
- YndigoBlue.Velocity.dll
Represents the ST_Centroid spatial analysis function that computes the geometric center of a geometry.
public class SpatialCentroid : Function, IElement, ICheckItem, IDefaultItem, IFilterItem- Inheritance
-
SpatialCentroid
- Implements
Remarks
Warning
Spatial functions are not available in the Community Edition of Velocity. They require the Full Edition.
The ST_Centroid function returns a point representing the mathematical centroid (center of mass) of the input geometry. For polygons, this is the center of gravity assuming uniform density. For lines, it's the center of the line's extent. For multi-part geometries, it's the weighted center of all parts. Note that the centroid may not lie within the geometry itself (e.g., for C-shaped polygons). Useful for labeling, finding centers, or proximity analysis. OGC-compliant.
Return Type: Always returns a POINT geometry.
Example Results (using test geometries):
| Shape | Centroid |
|---|---|
| PY0 (4°×4° square) | POINT(-98 42) - center of rectangle |
| PY1 (0.5°×1° rectangle) | POINT(-98.25 41.5) - center of rectangle |
| PY2 (1°×3° rectangle) | POINT(-93.5 40.5) - center of rectangle |
| PY3 (triangle) | POINT(-95.33 41.5) - centroid of triangle |
| PY4 (2°×1.5° rectangle) | POINT(-100 44.25) - center of rectangle |
| LN1 (vertical line) | POINT(-97 42) - midpoint of line |
| PT1, PT2 (points) | Returns the point itself |
Constructors
- SpatialCentroid(Geometry)
Initializes a new instance of ST_Centroid with a geometry literal.
- SpatialCentroid(Column)
Initializes a new instance of ST_Centroid with a spatial column.
- SpatialCentroid(Function)
Initializes a new instance of ST_Centroid for a function result (e.g., from another spatial operation).
- SpatialCentroid(Geography)
Initializes a new instance of ST_Centroid with a geography literal.