These functions produce or operate on bounding boxes. They can also provide and accept geometry values, by using automatic or explicit casts.

See also PostGIS_BoxFunctions.

# Bounding Box Functions

Box2D

Returns a BOX2D representing the 2D extent of a geometry.

    			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.

&curve_support;

&P_support;

&T_support;

### 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, ST_GeomFromText

Box3D

Returns a BOX3D representing the 3D extent of a geometry.

    			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.

&curve_support;

&P_support;

&T_support;

&Z_support;

### 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

Box2D, ST_GeomFromEWKT

ST_EstimatedExtent

Returns the estimated extent of a spatial table.

    			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.

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.

Availability: 1.0.0

Changed: 2.1.0. Up to 2.0.x this was called ST_Estimated_Extent.

&curve_support;

### 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_Extent, ST_3DExtent

ST_Expand

Returns a bounding box expanded from another bounding box or a geometry.

    			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.

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.

&P_support;

&T_support;

### Examples

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.

    			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.

ST_Extent returns boxes with only X and Y ordinates even with 3D geometries. To return XYZ ordinates use ST_3DExtent.

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.

&P_support;

&T_support;

### Examples

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.

    			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.

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

&Z_support;

&curve_support;

&P_support;

&T_support;

### 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.

    			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_Point, ST_SetSRID, ST_SRID

ST_3DMakeBox

Creates a BOX3D defined by two 3D point geometries.

    			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.

    			float ST_XMax
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the X maxima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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.

    			float ST_XMin
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the X minima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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.

    			float ST_YMax
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the Y maxima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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.

    			float ST_YMin
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the Y minima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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.

    			float ST_ZMax
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the Z maxima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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.

    			float ST_ZMin
    			box3d  aGeomorBox2DorBox3D

### Description

Returns the Z minima of a 2D or 3D bounding box or a geometry.

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.

&Z_support;

&curve_support;

### 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