Parametric circles, ellipses, and wedges

You can create and query parametric circles, ellipses, or wedges in ST_Geometry columns using the ST_Geometry function.

Parametric circles, ellipses, and wedges are polygons that are defined by specific parameters, such as coordinate values, angles, and radii. The database stores these parameters instead of specific vertices and lines. By storing the parameters that define the shape, parametric shapes can be more accurate and use less storage space than storing them as many-sided polygon representations. The use of parametric shapes also allows the inclusion of z-coordinate and measure (m)-value parameters.

Seven parameters are expected when creating a circle:

Nine parameters are expected when creating an ellipse:

Ten parameters are expected when creating a wedge:

All radii, including the semimajor and semiminor axes and inner and outer radii, are defined in the units determined by the coordinate reference specified with the SRID.

See the ST_Geometry function for syntax and examples to create a parametric circle, ellipse, or wedge.

Related Topics

6/19/2015