Geometric Functions and Operators
Geometric Operators
Description: Translation
For example:
```
postgres=# SELECT box '((0,0),(1,1))' + point '(2.0,0)' AS RESULT;
result
-------------
(3,1),(2,0)
(1 row)
```
Description: Translation
For example:
```
postgres=# SELECT box '((0,0),(1,1))' - point '(2.0,0)' AS RESULT;
result
---------------
(-1,1),(-2,0)
(1 row)
```
*
Description: Scaling out/rotation
For example:
postgres=# SELECT box '((0,0),(1,1))' * point '(2.0,0)' AS RESULT; result ------------- (2,2),(0,0) (1 row)
/
Description: Scaling in/rotation
For example:
postgres=# SELECT box '((0,0),(2,2))' / point '(2.0,0)' AS RESULT; result ------------- (1,1),(0,0) (1 row)
#
Description: Box of intersection
For example:
postgres=# SELECT box '((1,-1),(-1,1))' # box '((1,1),(-2,-2))' AS RESULT; result --------------- (1,1),(-1,-1) (1 row)
#
Description: Number of paths or polygon vertexes
For example:
postgres=# SELECT # path'((1,0),(0,1),(-1,0))' AS RESULT; result -------- 3 (1 row)
@-@
Description: Length or circumference
For example:
postgres=# SELECT @-@ path '((0,0),(1,0))' AS RESULT; result -------- 2 (1 row)
@@
Description: Center of box
For example:
postgres=# SELECT @@ circle '((0,0),10)' AS RESULT; result -------- (0,0) (1 row)
<->
Description: Distance between the two figures.
For example:
postgres=# SELECT circle '((0,0),1)' <-> circle '((5,0),1)' AS RESULT; result -------- 3 (1 row)
&&
Description: Overlaps? (One point in common makes this true.)
For example:
postgres=# SELECT box '((0,0),(1,1))' && box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
«
Description: Is strictly left of (no common horizontal coordinate)?
For example:
postgres=# SELECT circle '((0,0),1)' << circle '((5,0),1)' AS RESULT; result -------- t (1 row)
>>
Description: Is strictly right of (no common horizontal coordinate)?
For example:
postgres=# SELECT circle '((5,0),1)' >> circle '((0,0),1)' AS RESULT; result -------- t (1 row)
&<
Description: Does not extend to the right of?
For example:
postgres=# SELECT box '((0,0),(1,1))' &< box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
&>
Description: Does not extend to the left of?
For example:
postgres=# SELECT box '((0,0),(3,3))' &> box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
«|
Description: Is strictly below (no common horizontal coordinate)?
For example:
postgres=# SELECT box '((0,0),(3,3))' <<| box '((3,4),(5,5))' AS RESULT; result -------- t (1 row)
|>>
Description: Is strictly above (no common horizontal coordinate)?
For example:
postgres=# SELECT box '((3,4),(5,5))' |>> box '((0,0),(3,3))' AS RESULT; result -------- t (1 row)
&<|
Description: Does not extend above?
For example:
postgres=# SELECT box '((0,0),(1,1))' &<| box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
|&>
Description: Does not extend below?
For example:
postgres=# SELECT box '((0,0),(3,3))' |&> box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
<^
Description: Is below (allows touching)?
For example:
postgres=# SELECT box '((0,0),(-3,-3))' <^ box '((0,0),(2,2))' AS RESULT; result -------- t (1 row)
>^
Description: Is above (allows touching)?
For example:
postgres=# SELECT box '((0,0),(2,2))' >^ box '((0,0),(-3,-3))' AS RESULT; result -------- t (1 row)
?#
Description: Intersect?
For example:
postgres=# SELECT lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))' AS RESULT; result -------- t (1 row)
?-
Description: Is horizontal?
For example:
postgres=# SELECT ?- lseg '((-1,0),(1,0))' AS RESULT; result -------- t (1 row)
?-
Description: Are horizontally aligned?
For example:
postgres=# SELECT point '(1,0)' ?- point '(0,0)' AS RESULT; result -------- t (1 row)
?|
Description: Is vertical?
For example:
postgres=# SELECT ?| lseg '((-1,0),(1,0))' AS RESULT; result -------- f (1 row)
?|
Description: Are vertically aligned?
For example:
postgres=# SELECT point '(0,1)' ?| point '(0,0)' AS RESULT; result -------- t (1 row)
?-|
Description: Are perpendicular?
For example:
postgres=# SELECT lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))' AS RESULT; result -------- t (1 row)
?||
Description: Are parallel?
For example:
postgres=# SELECT lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))' AS RESULT; result -------- t (1 row)
@>
Description: Contains?
For example:
postgres=# SELECT circle '((0,0),2)' @> point '(1,1)' AS RESULT; result -------- t (1 row)
<@
Description: Contained in or on?
For example:
postgres=# SELECT point '(1,1)' <@ circle '((0,0),2)' AS RESULT; result -------- t (1 row)
~=
Description: Same as?
For example:
postgres=# SELECT polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))' AS RESULT; result -------- t (1 row)
Geometric Functions
area(object)
Description: Area calculation
Return type: double precision
For example:
postgres=# SELECT area(box '((0,0),(1,1))') AS RESULT; result -------- 1 (1 row)
center(object)
Description: Figure center calculation
Return type: point
For example:
postgres=# SELECT center(box '((0,0),(1,2))') AS RESULT; result --------- (0.5,1) (1 row)
diameter(circle)
Description: Circle diameter calculation
Return type: double precision
For example:
postgres=# SELECT diameter(circle '((0,0),2.0)') AS RESULT; result -------- 4 (1 row)
height(box)
Description: Vertical size of box
Return type: double precision
For example:
postgres=# SELECT height(box '((0,0),(1,1))') AS RESULT; result -------- 1 (1 row)
isclosed(path)
Description: A closed path?
Return type: Boolean
For example:
postgres=# SELECT isclosed(path '((0,0),(1,1),(2,0))') AS RESULT; result -------- t (1 row)
isopen(path)
Description: An open path?
Return type: Boolean
For example:
postgres=# SELECT isopen(path '[(0,0),(1,1),(2,0)]') AS RESULT; result -------- t (1 row)
length(object)
Description: Length calculation
Return type: double precision
For example:
postgres=# SELECT length(path '((-1,0),(1,0))') AS RESULT; result -------- 4 (1 row)
npoints(path)
Description: Number of points in path
Return type: int
For example:
postgres=# SELECT npoints(path '[(0,0),(1,1),(2,0)]') AS RESULT; result -------- 3 (1 row)
npoints(polygon)
Description: Number of points in polygon
Return type: int
For example:
postgres=# SELECT npoints(polygon '((1,1),(0,0))') AS RESULT; result -------- 2 (1 row)
pclose(path)
Description: Converts path to closed.
Return type: path
For example:
postgres=# SELECT pclose(path '[(0,0),(1,1),(2,0)]') AS RESULT; result --------------------- ((0,0),(1,1),(2,0)) (1 row)
popen(path)
Description: Converts path to open.
Return type: path
For example:
postgres=# SELECT popen(path '((0,0),(1,1),(2,0))') AS RESULT; result --------------------- [(0,0),(1,1),(2,0)] (1 row)
radius(circle)
Description: Circle diameter calculation
Return type: double precision
For example:
postgres=# SELECT radius(circle '((0,0),2.0)') AS RESULT; result -------- 2 (1 row)
width(box)
Description: Horizontal size of box
Return type: double precision
For example:
postgres=# SELECT width(box '((0,0),(1,1))') AS RESULT; result -------- 1 (1 row)
Geometric Type Conversion Functions
box(circle)
Description: Circle to box
Return type: box
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# SELECT circle(point '(0,0)', 2.0) AS RESULT; result ----------- <(0,0),2> (1 row)
circle(polygon)
Description: Polygon to circle
Return type: circle
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# SELECT point(23.4, -44.5) AS RESULT; result -------------- (23.4,-44.5) (1 row)
point(box)
Description: Center of box
Return type: point
For example:
postgres=# SELECT point(box '((-1,0),(1,0))') AS RESULT; result -------- (0,0) (1 row)
point(circle)
Description: Center of circle
Return type: point
For example:
postgres=# SELECT point(circle '((0,0),2.0)') AS RESULT; result -------- (0,0) (1 row)
point(lseg)
Description: Center of line segment
Return type: point
For example:
postgres=# SELECT point(lseg '((-1,0),(1,0))') AS RESULT; result -------- (0,0) (1 row)
point(polygon)
Description: Center of polygon
Return type: point
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# 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
For example:
postgres=# SELECT polygon(path '((0,0),(1,1),(2,0))') AS RESULT; result --------------------- ((0,0),(1,1),(2,0)) (1 row)