Parametric circles and ellipses

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

Parametric circles and ellipses 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 circles and ellipses can be more accurate and use less storage space than storing circles and ellipses as many-sided polygon representations. The use of parametric circles and ellipses also allows the inclusion of z-coordinate and m-value parameters.

Seven parameters are expected when creating a circle:

Nine parameters are expected when creating an ellipse:

Radii, including the semimajor and semiminor axes, 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 and ellipse.

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