ST_BoundingDiagonal

Name

ST_BoundingDiagonal — Returns the diagonal of the supplied geometry's bounding box.

Synopsis

geometry ST_BoundingDiagonal ( geometry geom , boolean fits=false ) ;

Description

Returns the diagonal of the supplied geometry's bounding box as linestring. If the input geometry is empty, the diagonal line is also empty, otherwise it is a 2-points linestring with minimum values of each dimension in its start point and maximum values in its end point.

The returned linestring geometry always retains SRID and dimensionality (Z and M presence) of the input geometry.

The fits parameter specifies if the best fit is needed. If false, the diagonal of a somewhat larger bounding box can be accepted (is faster to obtain for geometries with a lot of vertices). In any case the bounding box of the returned diagonal line always covers the input geometry.

[Note]

In degenerate cases (a single vertex in input) the returned linestring will be topologically invalid (no interior). This does not make the return semantically invalid.

Availability: 2.2.0

This function supports 3d and will not drop the z-index.

This function supports M coordinates.

Examples

-- Get the minimum X in a buffer around a point
SELECT ST_X(ST_StartPoint(ST_BoundingDiagonal(
  ST_Buffer(ST_MakePoint(0,0),10)
)));
 st_x
------
  -10