Bounding Box Functions
Box2D
Returns a BOX2D representing the 2D extent of a geometry.
Synopsis
box2d Box2D(geometry geom)
Description
Returns a box2d_type representing the 2D extent of the geometry.
Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.
Examples
SELECT Box2D(ST_GeomFromText('LINESTRING(1 2, 3 4, 5 6)'));
box2d
---------
BOX(1 2,5 6)
SELECT Box2D(ST_GeomFromText('CIRCULARSTRING(220268 150415,220227 150505,220227 150406)'));
box2d
--------
BOX(220186.984375 150406,220288.25 150506.140625)
See Also
Box3D
Returns a BOX3D representing the 3D extent of a geometry.
Synopsis
box3d Box3D(geometry geom)
Description
Returns a box3d_type representing the 3D extent of the geometry.
Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.
Examples
SELECT Box3D(ST_GeomFromEWKT('LINESTRING(1 2 3, 3 4 5, 5 6 5)'));
Box3d
---------
BOX3D(1 2 3,5 6 5)
SELECT Box3D(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 1,220227 150406 1)'));
Box3d
--------
BOX3D(220227 150406 1,220268 150415 1)
See Also
ST_EstimatedExtent
Returns the estimated extent of a spatial table.
Synopsis
box2d ST_EstimatedExtent(text schema_name, text table_name, text geocolumn_name, boolean parent_only)
box2d ST_EstimatedExtent(text schema_name, text table_name, text geocolumn_name)
box2d ST_EstimatedExtent(text table_name, text geocolumn_name)
Description
Returns the estimated extent of a spatial table as a box2d_type. The current schema is used if not specified. The estimated extent is taken from the geometry column's statistics. This is usually much faster than computing the exact extent of the table using ST_Extent or ST_3DExtent.
The default behavior is to also use statistics collected from child tables (tables with INHERITS) if available. If parent_only is set to TRUE, only statistics for the given table are used and child tables are ignored.
For PostgreSQL >= 8.0.0 statistics are gathered by VACUUM ANALYZE and the result extent will be about 95% of the actual one. For PostgreSQL < 8.0.0 statistics are gathered by running update_geometry_stats() and the result extent is exact.
Note
In the absence of statistics (empty table or no ANALYZE called) this function returns NULL. Prior to version 1.5.4 an exception was thrown instead.
Note
Escaping names for tables and/or namespaces that include special characters and quotes may require special handling. A user notes: "For schemas and tables, use identifier escaping rules to produce a double-quoted string, and afterwards remove the first and last double-quote character. For geometry column pass as is."
Availability: 1.0.0
Changed: 2.1.0. Up to 2.0.x this was called ST_Estimated_Extent.
Examples
SELECT ST_EstimatedExtent('ny', 'edges', 'geom');
--result--
BOX(-8877653 4912316,-8010225.5 5589284)
SELECT ST_EstimatedExtent('feature_poly', 'geom');
--result--
BOX(-124.659652709961 24.6830825805664,-67.7798080444336 49.0012092590332)
See Also
ST_Expand
Returns a bounding box expanded from another bounding box or a geometry.
Synopsis
geometry ST_Expand(geometry geom, float units_to_expand)
geometry ST_Expand(geometry geom, float dx, float dy, float dz=0, float dm=0)
box2d ST_Expand(box2d box, float units_to_expand)
box2d ST_Expand(box2d box, float dx, float dy)
box3d ST_Expand(box3d box, float units_to_expand)
box3d ST_Expand(box3d box, float dx, float dy, float dz=0)
Description
Returns a bounding box expanded from the bounding box of the input, either by specifying a single distance with which the box should be expanded on both axes, or by specifying an expansion distance for each axis. Uses double-precision. Can be used for distance queries, or to add a bounding box filter to a query to take advantage of a spatial index.
In addition to the version of ST_Expand accepting and returning a geometry, variants are provided that accept and return box2d_type and box3d_type data types.
Distances are in the units of the spatial reference system of the input.
ST_Expand is similar to ST_Buffer, except while buffering expands a geometry in all directions, ST_Expand expands the bounding box along each axis.
Note
Pre version 1.3, ST_Expand was used in conjunction with ST_Distance to do indexable distance queries. For example, geom && ST_Expand('POINT(10 20)', 10) AND ST_Distance(geom, 'POINT(10 20)') < 10. This has been replaced by the simpler and more efficient ST_DWithin function.
Availability: 1.5.0 behavior changed to output double precision instead of float4 coordinates.
Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.
Enhanced: 2.3.0 support was added to expand a box by different amounts in different dimensions.
Examples
Note
Examples below use US National Atlas Equal Area (SRID=2163) which is a meter projection
--10 meter expanded box around bbox of a linestring
SELECT CAST(ST_Expand(ST_GeomFromText('LINESTRING(2312980 110676,2312923 110701,2312892 110714)', 2163),10) As box2d);
st_expand
------------------------------------
BOX(2312882 110666,2312990 110724)
--10 meter expanded 3D box of a 3D box
SELECT ST_Expand(CAST('BOX3D(778783 2951741 1,794875 2970042.61545891 10)' As box3d),10)
st_expand
-----------------------------------------------------
BOX3D(778773 2951731 -9,794885 2970052.61545891 20)
--10 meter geometry astext rep of a expand box around a point geometry
SELECT ST_AsEWKT(ST_Expand(ST_GeomFromEWKT('SRID=2163;POINT(2312980 110676)'),10));
st_asewkt
-------------------------------------------------------------------------------------------------
SRID=2163;POLYGON((2312970 110666,2312970 110686,2312990 110686,2312990 110666,2312970 110666))
See Also
ST_Buffer, ST_DWithin, ST_SRID
ST_Extent
Aggregate function that returns the bounding box of geometries.
Synopsis
box2d ST_Extent(geometry set geomfield)
Description
An aggregate function that returns a box2d_type bounding box that bounds a set of geometries.
The bounding box coordinates are in the spatial reference system of the input geometries.
ST_Extent is similar in concept to Oracle Spatial/Locator's SDO_AGGR_MBR.
Note
ST_Extent returns boxes with only X and Y ordinates even with 3D geometries. To return XYZ ordinates use ST_3DExtent.
Note
The returned box3d value does not include a SRID. Use ST_SetSRID to convert it into a geometry with SRID metadata. The SRID is the same as the input geometries.
Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.
Examples
Note
Examples below use Massachusetts State Plane ft (SRID=2249)
SELECT ST_Extent(geom) as bextent FROM sometable;
st_bextent
------------------------------------
BOX(739651.875 2908247.25,794875.8125 2970042.75)
--Return extent of each category of geometries
SELECT ST_Extent(geom) as bextent
FROM sometable
GROUP BY category ORDER BY category;
bextent | name
----------------------------------------------------+----------------
BOX(778783.5625 2951741.25,794875.8125 2970042.75) | A
BOX(751315.8125 2919164.75,765202.6875 2935417.25) | B
BOX(739651.875 2917394.75,756688.375 2935866) | C
--Force back into a geometry
-- and render the extended text representation of that geometry
SELECT ST_SetSRID(ST_Extent(geom),2249) as bextent FROM sometable;
bextent
--------------------------------------------------------------------------------
SRID=2249;POLYGON((739651.875 2908247.25,739651.875 2970042.75,794875.8125 2970042.75,
794875.8125 2908247.25,739651.875 2908247.25))
See Also
ST_EstimatedExtent, ST_3DExtent, ST_SetSRID
ST_3DExtent
Aggregate function that returns the 3D bounding box of geometries.
Synopsis
box3d ST_3DExtent(geometry set geomfield)
Description
An aggregate function that returns a box3d_type (includes Z ordinate) bounding box that bounds a set of geometries.
The bounding box coordinates are in the spatial reference system of the input geometries.
Note
The returned box3d value does not include a SRID. Use ST_SetSRID to convert it into a geometry with SRID metadata. The SRID is the same as the input geometries.
Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.
Changed: 2.0.0 In prior versions this used to be called ST_Extent3D
Examples
SELECT ST_3DExtent(foo.geom) As b3extent
FROM (SELECT ST_MakePoint(x,y,z) As geom
FROM generate_series(1,3) As x
CROSS JOIN generate_series(1,2) As y
CROSS JOIN generate_series(0,2) As Z) As foo;
b3extent
--------------------
BOX3D(1 1 0,3 2 2)
--Get the extent of various elevated circular strings
SELECT ST_3DExtent(foo.geom) As b3extent
FROM (SELECT ST_Translate(ST_Force_3DZ(ST_LineToCurve(ST_Buffer(ST_Point(x,y),1))),0,0,z) As geom
FROM generate_series(1,3) As x
CROSS JOIN generate_series(1,2) As y
CROSS JOIN generate_series(0,2) As Z) As foo;
b3extent
--------------------
BOX3D(1 0 0,4 2 2)
See Also
ST_Extent, ST_Force_3DZ, ST_SetSRID
ST_MakeBox2D
Creates a BOX2D defined by two 2D point geometries.
Synopsis
box2d ST_MakeBox2D(geometry pointLowLeft, geometry pointUpRight)
Description
Creates a box2d_type defined by two Point geometries. This is useful for doing range queries.
Examples
--Return all features that fall reside or partly reside in a US national atlas coordinate bounding box
--It is assumed here that the geometries are stored with SRID = 2163 (US National atlas equal area)
SELECT feature_id, feature_name, geom
FROM features
WHERE geom && ST_SetSRID(ST_MakeBox2D(ST_Point(-989502.1875, 528439.5625),
ST_Point(-987121.375 ,529933.1875)),2163)
See Also
ST_3DMakeBox
Creates a BOX3D defined by two 3D point geometries.
Synopsis
box3d ST_3DMakeBox(geometry point3DLowLeftBottom, geometry point3DUpRightTop)
Description
Creates a box3d_type defined by two 3D Point geometries.
This function supports 3D and will not drop the z-index.
Changed: 2.0.0 In prior versions this used to be called ST_MakeBox3D
Examples
SELECT ST_3DMakeBox(ST_MakePoint(-989502.1875, 528439.5625, 10),
ST_MakePoint(-987121.375 ,529933.1875, 10)) As abb3d
--bb3d--
--------
BOX3D(-989502.1875 528439.5625 10,-987121.375 529933.1875 10)
See Also
ST_MakePoint, ST_SetSRID, ST_SRID
ST_XMax
Returns the X maxima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_XMax(box3d aGeomorBox2DorBox3D)
Description
Returns the X maxima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However, it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_XMax('BOX3D(1 2 3, 4 5 6)');
st_xmax
-------
4
SELECT ST_XMax(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'));
st_xmax
-------
5
SELECT ST_XMax(CAST('BOX(-3 2, 3 4)' As box2d));
st_xmax
-------
3
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_XMax('LINESTRING(1 3, 5 6)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_XMax(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_xmax
--------
220288.248780547
See Also
ST_XMin, ST_YMax, ST_YMin, ST_ZMax, ST_ZMin
ST_XMin
Returns the X minima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_XMin(box3d aGeomorBox2DorBox3D)
Description
Returns the X minima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_XMin('BOX3D(1 2 3, 4 5 6)');
st_xmin
-------
1
SELECT ST_XMin(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'));
st_xmin
-------
1
SELECT ST_XMin(CAST('BOX(-3 2, 3 4)' As box2d));
st_xmin
-------
-3
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_XMin('LINESTRING(1 3, 5 6)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_XMin(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_xmin
--------
220186.995121892
See Also
ST_XMax, ST_YMax, ST_YMin, ST_ZMax, ST_ZMin
ST_YMax
Returns the Y maxima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_YMax(box3d aGeomorBox2DorBox3D)
Description
Returns the Y maxima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_YMax('BOX3D(1 2 3, 4 5 6)');
st_ymax
-------
5
SELECT ST_YMax(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'));
st_ymax
-------
6
SELECT ST_YMax(CAST('BOX(-3 2, 3 4)' As box2d));
st_ymax
-------
4
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_YMax('LINESTRING(1 3, 5 6)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_YMax(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_ymax
--------
150506.126829327
See Also
ST_XMin, ST_XMax, ST_YMin, ST_ZMax, ST_ZMin
ST_YMin
Returns the Y minima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_YMin(box3d aGeomorBox2DorBox3D)
Description
Returns the Y minima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_YMin('BOX3D(1 2 3, 4 5 6)');
st_ymin
-------
2
SELECT ST_YMin(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'));
st_ymin
-------
3
SELECT ST_YMin(CAST('BOX(-3 2, 3 4)' As box2d));
st_ymin
-------
2
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_YMin('LINESTRING(1 3, 5 6)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_YMin(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_ymin
--------
150406
See Also
ST_GeomFromEWKT, ST_XMin, ST_XMax, ST_YMax, ST_ZMax, ST_ZMin
ST_ZMax
Returns the Z maxima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_ZMax(box3d aGeomorBox2DorBox3D)
Description
Returns the Z maxima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_ZMax('BOX3D(1 2 3, 4 5 6)');
st_zmax
-------
6
SELECT ST_ZMax(ST_GeomFromEWKT('LINESTRING(1 3 4, 5 6 7)'));
st_zmax
-------
7
SELECT ST_ZMax('BOX3D(-3 2 1, 3 4 1)' );
st_zmax
-------
1
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_ZMax('LINESTRING(1 3 4, 5 6 7)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_ZMax(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_zmax
--------
3
See Also
ST_GeomFromEWKT, ST_XMin, ST_XMax, ST_YMax, ST_YMin, ST_ZMax
ST_ZMin
Returns the Z minima of a 2D or 3D bounding box or a geometry.
Synopsis
float ST_ZMin(box3d aGeomorBox2DorBox3D)
Description
Returns the Z minima of a 2D or 3D bounding box or a geometry.
Note
Although this function is only defined for box3d, it also works for box2d and geometry values due to automatic casting. However it will not accept a geometry or box2d text representation, since those do not auto-cast.
Examples
SELECT ST_ZMin('BOX3D(1 2 3, 4 5 6)');
st_zmin
-------
3
SELECT ST_ZMin(ST_GeomFromEWKT('LINESTRING(1 3 4, 5 6 7)'));
st_zmin
-------
4
SELECT ST_ZMin('BOX3D(-3 2 1, 3 4 1)' );
st_zmin
-------
1
--Observe THIS DOES NOT WORK because it will try to auto-cast the string representation to a BOX3D
SELECT ST_ZMin('LINESTRING(1 3 4, 5 6 7)');
--ERROR: BOX3D parser - doesn't start with BOX3D(
SELECT ST_ZMin(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 2,220227 150406 3)'));
st_zmin
--------
1
See Also
ST_GeomFromEWKT, ST_GeomFromText, ST_XMin, ST_XMax, ST_YMax, ST_YMin, ST_ZMax