Name
ST_Scale — Scales a geometry by given factors.
Synopsis
geometry ST_Scale(geometry geomA, float XFactor, float YFactor, float ZFactor);
geometry ST_Scale(geometry geomA, float XFactor, float YFactor);
geometry ST_Scale(geometry geom, geometry factor);
geometry ST_Scale(geometry geom, geometry factor, geometry origin);
Descrizione
Scales the geometry to a new size by multiplying the ordinates with the corresponding factor parameters.
The version taking a geometry as the factor parameter allows passing a 2d, 3dm, 3dz or 4d point to set scaling factor for all supported dimensions. Missing dimensions in the factor point are equivalent to no scaling the corresponding dimension.
The three-geometry variant allows a "false origin" for the scaling to be passed in. This allows "scaling in place", for example using the centroid of the geometry as the false origin. Without a false origin, scaling takes place relative to the actual origin, so all coordinates are just multiplied by the scale factor.
![[Note]](../images/note.png)
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Prior to 1.3.4, this function crashes if used with geometries that contain CURVES. This is fixed in 1.3.4+ |
Availability: 1.1.0.
Migliorato: Nella 2.0.0 è stato introdotto il supporto per le superfici poliedriche, i triangoli e i TIN.
Enhanced: 2.2.0 support for scaling all dimension (factor parameter) was introduced.
Enhanced: 2.5.0 support for scaling relative to a local origin (origin parameter) was introduced.
Questa funzione supporta le Polyhedral Surface.
Questa funzione supporta il 3d e non distrugge gli z-index.
Questo metodo supporta le Curve e le Circular String.
Questa funzione supporta i Triangoli e le Triangulated Irregular Network Surfaces (TIN).
Questa funzione supporta le coordinate M.
Esempi
This example scales X, Y, and Z values.
SELECT ST_AsEWKT(ST_Scale(ST_GeomFromEWKT('LINESTRING(1 2 3, 1 1 1)'), 0.5, 0.75, 0.8));
LINESTRING(0.5 1.5 2.4,0.5 0.75 0.8)
This example scales X and Y values.
SELECT ST_AsEWKT(ST_Scale(ST_GeomFromEWKT('LINESTRING(1 2 3, 1 1 1)'), 0.5, 0.75));
LINESTRING(0.5 1.5 3,0.5 0.75 1)
This example scales X, Y, Z, and M values.
SELECT ST_AsEWKT(ST_Scale(ST_GeomFromEWKT('LINESTRING(1 2 3 4, 1 1 1 1)'),
ST_MakePoint(0.5, 0.75, 2, -1)));
LINESTRING(0.5 1.5 6 -4,0.5 0.75 2 -1)
This example scales X and Y values using a false origin.
SELECT ST_AsText(ST_Scale('LINESTRING(1 1, 2 2)', 'POINT(2 2)', 'POINT(1 1)'::geometry));
LINESTRING(1 1,3 3)