Geometric Type Conversion Functions¶
box(circle)¶
Description: Circle to box
Return type: box
Example:
SELECT box(circle '((0,0),2.0)') AS RESULT;
result
---------------------------------------------------------------------------
(1.41421356237309,1.41421356237309),(-1.41421356237309,-1.41421356237309)
(1 row)
box(point, point)¶
Description: Points to box
Return type: box
Example:
SELECT box(point '(0,0)', point '(1,1)') AS RESULT;
result
-------------
(1,1),(0,0)
(1 row)
box(polygon)¶
Description: Polygon to box
Return type: box
Example:
SELECT box(polygon '((0,0),(1,1),(2,0))') AS RESULT;
result
-------------
(2,1),(0,0)
(1 row)
circle(box)¶
Description: Box to circle
Return type: circle
Example:
SELECT circle(box '((0,0),(1,1))') AS RESULT;
result
-------------------------------
<(0.5,0.5),0.707106781186548>
(1 row)
circle(point, double precision)¶
Description: Center and radius to circle
Return type: circle
Example:
SELECT circle(point '(0,0)', 2.0) AS RESULT;
result
-----------
<(0,0),2>
(1 row)
circle(polygon)¶
Description: Polygon to circle
Return type: circle
Example:
SELECT circle(polygon '((0,0),(1,1),(2,0))') AS RESULT;
result
-------------------------------------------
<(1,0.333333333333333),0.924950591148529>
(1 row)
lseg(box)¶
Description: Box diagonal to line segment
Return type: lseg
Example:
SELECT lseg(box '((-1,0),(1,0))') AS RESULT;
result
----------------
[(1,0),(-1,0)]
(1 row)
lseg(point, point)¶
Description: Points to line segment
Return type: lseg
Example:
SELECT lseg(point '(-1,0)', point '(1,0)') AS RESULT;
result
----------------
[(-1,0),(1,0)]
(1 row)
path(polygon)¶
Description: Polygon to path
Return type: path
Example:
SELECT path(polygon '((0,0),(1,1),(2,0))') AS RESULT;
result
---------------------
((0,0),(1,1),(2,0))
(1 row)
point(double precision, double precision)¶
Description: Points
Return type: point
Example:
SELECT point(23.4, -44.5) AS RESULT;
result
--------------
(23.4,-44.5)
(1 row)
point(box)¶
Description: Center of box
Return type: point
Example:
SELECT point(box '((-1,0),(1,0))') AS RESULT;
result
--------
(0,0)
(1 row)
point(circle)¶
Description: Center of circle
Return type: point
Example:
SELECT point(circle '((0,0),2.0)') AS RESULT;
result
--------
(0,0)
(1 row)
point(lseg)¶
Description: Center of line segment
Return type: point
Example:
SELECT point(lseg '((-1,0),(1,0))') AS RESULT;
result
--------
(0,0)
(1 row)
point(polygon)¶
Description: Center of polygon
Return type: point
Example:
SELECT point(polygon '((0,0),(1,1),(2,0))') AS RESULT;
result
-----------------------
(1,0.333333333333333)
(1 row)
polygon(box)¶
Description: Box to 4-point polygon
Return type: polygon
Example:
SELECT polygon(box '((0,0),(1,1))') AS RESULT;
result
---------------------------
((0,0),(0,1),(1,1),(1,0))
(1 row)
polygon(circle)¶
Description: Circle to 12-point polygon
Return type: polygon
Example:
SELECT polygon(circle '((0,0),2.0)') AS RESULT;
result
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
((-2,0),(-1.73205080756888,1),(-1,1.73205080756888),(-1.22464679914735e-16,2),(1,1.73205080756888),(1.73205080756888,1),(2,2.44929359829471e-16),(1.73205080756888,-0.999999999999999),(1,-1.73205080756888),(3.67394039744206e-16,-2),(-0.999999999999999,-1.73205080756888),(-1.73205080756888,-1))
(1 row)
polygon(npts, circle)¶
Description: Circle to npts-point polygon
Return type: polygon
Example:
SELECT polygon(12, circle '((0,0),2.0)') AS RESULT;
result
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
((-2,0),(-1.73205080756888,1),(-1,1.73205080756888),(-1.22464679914735e-16,2),(1,1.73205080756888),(1.73205080756888,1),(2,2.44929359829471e-16),(1.73205080756888,-0.999999999999999),(1,-1.73205080756888),(3.67394039744206e-16,-2),(-0.999999999999999,-1.73205080756888),(-1.73205080756888,-1))
(1 row)
polygon(path)¶
Description: Path to polygon
Return type: polygon
Example:
SELECT polygon(path '((0,0),(1,1),(2,0))') AS RESULT;
result
---------------------
((0,0),(1,1),(2,0))
(1 row)