class Union(expr1, expr2, **extra) Availability: MySQL (≥ 5.6.1), PostGIS, Oracle, SpatiaLite Accepts two geographic fields or expressions and returns the union of both geometries.

class Translate(expression, x, y, z=0.0, **extra) Availability: PostGIS, SpatiaLite Accepts a single geographic field or expression and returns a geometry with its coordinates offset by the x, y, and optionally z numeric parameters.

class Transform(expression, srid, **extra) Availability: PostGIS, Oracle, SpatiaLite Accepts a geographic field or expression and a SRID integer code, and returns the transformed geometry to the spatial reference system specified by the srid parameter. Note What spatial reference system an integer SRID corresponds to may depend on the spatial database used. In other words, the SRID numbers used for Oracle are not necessarily the same as those used by PostGIS.

class SymDifference(expr1, expr2, **extra) Availability: MySQL (≥ 5.6.1), PostGIS, Oracle, SpatiaLite Accepts two geographic fields or expressions and returns the geometric symmetric difference (union without the intersection) between the given parameters. Changed in Django 1.10: MySQL support was added.

class SnapToGrid(expression, *args, **extra) Availability: PostGIS, SpatiaLite (≥ 3.1) Accepts a single geographic field or expression and returns a geometry with all points snapped to the given grid. How the geometry is snapped to the grid depends on how many numeric (either float, integer, or long) arguments are given. Number of Arguments Description 1 A single size to snap both the X and Y grids to. 2 X and Y sizes to snap the grid to. 4 X, Y sizes and the corresponding X, Y origins.

class Scale(expression, x, y, z=0.0, **extra) Availability: PostGIS, SpatiaLite Accepts a single geographic field or expression and returns a geometry with scaled coordinates by multiplying them with the x, y, and optionally z parameters.

class Reverse(expression, **extra) Availability: PostGIS, Oracle, SpatiaLite (≥ 4.0) Accepts a single geographic field or expression and returns a geometry with reversed coordinates.

class PointOnSurface(expression, **extra) Availability: PostGIS, Oracle, SpatiaLite Accepts a single geographic field or expression and returns a Point geometry guaranteed to lie on the surface of the field; otherwise returns None.

class Perimeter(expression, **extra) Availability: PostGIS, Oracle, SpatiaLite (≥ 4.0) Accepts a single geographic field or expression and returns the perimeter of the geometry field as a Distance object. On MySQL, a raw float value is returned, as it’s not possible to automatically determine the unit of the field.

class NumPoints(expression, **extra) Availability: MySQL, PostGIS, Oracle, SpatiaLite Accepts a single geographic field or expression and returns the number of points in the first linestring in the geometry field; otherwise returns None.