ST_Affine

Syntax

geometry ST_Affine(geometry geomA, float a, float b, float c, float d, float e, float f, float g, float h, float i, float xoff, float yoff, float zoff);
geometry ST_Affine(geometry geomA, float a, float b, float d, float e, float xoff, float yoff);

Parameters

Description

Both overloads apply an affine transformation to all vertices in the geometry. Use the 13-parameter overload for 3D transformations, or the 7-parameter overload for 2D transformations.

13-parameter overload (3D)

The parameters map to the following transformation matrix:

/ a  b  c  xoff \
| d  e  f  yoff |
| g  h  i  zoff |
\ 0  0  0     1 /

Each vertex (x, y, z) is transformed as follows:

x' = a*x + b*y + c*z + xoff
y' = d*x + e*y + f*z + yoff
z' = g*x + h*y + i*z + zoff

7-parameter overload (2D)

The parameters map to the following transformation matrix:

/  a  b  0  xoff  \       /  a  b  xoff  \
|  d  e  0  yoff  | rsp.  |  d  e  yoff  |
|  0  0  1     0  |       \  0  0     1  /
\  0  0  0     1  /

Each vertex is transformed as follows:

x' = a*x + b*y + xoff
y' = d*x + e*y + yoff
z' = z

This is a special case of the 3D overload, with the z coordinate unchanged.

Both overloads support CircularString, curves, PolyhedralSurface, Triangle, TIN (Triangulated Irregular Network), and 3D geometry.

Examples

Rotate POINT(1 2 3) 180 degrees simultaneously on the x-, y-, and z-axes:

SELECT ST_AsEWKT(ST_Affine(ST_GeomFromEWKT('POINT(1 2 3)'),
                           cos(pi()), -sin(pi()), 0, sin(pi()), cos(pi()), -sin(pi()), 0, sin(pi()), cos(pi()), 0, 0, 0));
    st_asewkt
-----------------
 POINT(-1 -2 -3)
(1 row)