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Updated on 2022-06-11 GMT+08:00

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Geometric Functions and Operators

Geometric Operators

Description: Translation

For example:

SELECT box '((0,0),(1,1))' + point '(2.0,0)' AS RESULT;
   result    
-------------
 (3,1),(2,0)
(1 row)

Description: Translation

For example:

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:

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:

SELECT box '((0,0),(2,2))' / point '(2.0,0)' AS RESULT;
   result    
-------------
 (1,1),(0,0)
(1 row)

Description: Point or box of intersection

For example:

SELECT box'((1,-1),(-1,1))' # box'((1,1),(-1,-1))' AS RESULT;
 result 
--------
(1,1),(-1,-1)
(1 row)

Description: Number of paths or polygon vertexs

For example:

SELECT # path'((1,0),(0,1),(-1,0))' AS RESULT;
 result 
--------
      3
(1 row)

@-@

Description: Length or circumference

For example:

SELECT @-@ path '((0,0),(1,0))' AS RESULT;
 result 
--------
      2
(1 row)

Description: Center of box

For example:

SELECT @@ circle '((0,0),10)' AS RESULT;
 result 
--------
 (0,0)
(1 row)

Description: Closest point to first figure on second figure.

For example:

SELECT point '(0,0)' ## box '((2,0),(0,2))' AS RESULT;
 result 
--------
 (0,0)
(1 row)

<->

Description: Distance between the two figures.

For example:

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:

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:

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:

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:

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:

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:

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:

SELECT box '((3,4),(5,5))' |>> box '((0,0),(3,3))' AS RESULT;
 result 
--------
 t
(1 row)

&<|

Description: Does not extend above?

For example:

SELECT box '((0,0),(1,1))' &<| box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

|&>

Description: Does not extend below?

For example:

SELECT box '((0,0),(3,3))' |&> box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is below (allows touching)?

For example:

SELECT box '((0,0),(-3,-3))' <^ box '((0,0),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is above (allows touching)?

For example:

SELECT box '((0,0),(2,2))' >^ box '((0,0),(-3,-3))'  AS RESULT;
 result 
--------
 t
(1 row)

Description: Intersect?

For example:

SELECT lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is horizontal?

For example:

SELECT ?- lseg '((-1,0),(1,0))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Are horizontally aligned?

For example:

SELECT point '(1,0)' ?- point '(0,0)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Is vertical?

For example:

SELECT ?| lseg '((-1,0),(1,0))' AS RESULT;
 result 
--------
 f
(1 row)

Description: Are vertically aligned?

For example:

SELECT point '(0,1)' ?| point '(0,0)' AS RESULT;
 result 
--------
 t
(1 row)

?-|

Description: Are perpendicular?

For example:

SELECT lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))' AS RESULT;
 result 
--------
 t
(1 row)

?||

Description: Are parallel?

For example:

SELECT lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))' AS RESULT;
 result 
--------
 t
(1 row)

Description: Contains?

For example:

SELECT circle '((0,0),2)' @> point '(1,1)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Contained in or on?

For example:

SELECT point '(1,1)' <@ circle '((0,0),2)' AS RESULT;
 result 
--------
 t
(1 row)

Description: Same as?

For example:

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:

SELECT area(box '((0,0),(1,1))') AS RESULT;
 result 
--------
      1
(1 row)

center(object)

Description: Figure center calculation

Return type: point

For example:

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:

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:

SELECT height(box '((0,0),(1,1))') AS RESULT;
 result 
--------
      1
(1 row)

isclosed(path)

Description: A closed path?

Return type: boolean

For example:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

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:

SELECT polygon(path '((0,0),(1,1),(2,0))') AS RESULT;
       result        
---------------------
 ((0,0),(1,1),(2,0))
(1 row)

Parent topic: Functions and Operators

Previous topic: Type Conversion Functions

Next topic: Network Address Functions and Operators

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