The geometric types point, box, lseg, line, path, polygon, and circle have a large set of native support functions.
Table 5-6. Geometric Functions
| Function | Returns | Description | Example |
|---|---|---|---|
| area(box) | float8 | area of box | area('((0,0),(1,1))'::box) |
| area(circle) | float8 | area of circle | area('((0,0),2.0)'::circle) |
| box(box,box) | box | boxes to intersection box | box('((0,0),(1,1))','((0.5,0.5),(2,2))') |
| center(box) | point | center of object | center('((0,0),(1,2))'::box) |
| center(circle) | point | center of object | center('((0,0),2.0)'::circle) |
| diameter(circle) | float8 | diameter of circle | diameter('((0,0),2.0)'::circle) |
| height(box) | float8 | vertical size of box | height('((0,0),(1,1))'::box) |
| isclosed(path) | bool | a closed path? | isclosed('((0,0),(1,1),(2,0))'::path) |
| isopen(path) | bool | an open path? | isopen('[(0,0),(1,1),(2,0)]'::path) |
| length(lseg) | float8 | length of line segment | length('((-1,0),(1,0))'::lseg) |
| length(path) | float8 | length of path | length('((0,0),(1,1),(2,0))'::path) |
| pclose(path) | path | convert path to closed | popen('[(0,0),(1,1),(2,0)]'::path) |
| point(lseg,lseg) | point | intersection | point('((-1,0),(1,0))'::lseg,'((-2,-2),(2,2))'::lseg) |
| points(path) | int4 | number of points | points('[(0,0),(1,1),(2,0)]'::path) |
| popen(path) | path | convert path to open | popen('((0,0),(1,1),(2,0))'::path) |
| radius(circle) | float8 | radius of circle | radius('((0,0),2.0)'::circle) |
| width(box) | float8 | horizontal size | width('((0,0),(1,1))'::box) |
Table 5-7. Geometric Type Conversion Functions
| Function | Returns | Description | Example |
|---|---|---|---|
| box(circle) | box | convert circle to box | box('((0,0),2.0)'::circle) |
| box(point,point) | box | convert points to box | box('(0,0)'::point,'(1,1)'::point) |
| box(polygon) | box | convert polygon to box | box('((0,0),(1,1),(2,0))'::polygon) |
| circle(box) | circle | convert to circle | circle('((0,0),(1,1))'::box) |
| circle(point,float8) | circle | convert to circle | circle('(0,0)'::point,2.0) |
| lseg(box) | lseg | convert diagonal to lseg | lseg('((-1,0),(1,0))'::box) |
| lseg(point,point) | lseg | convert to lseg | lseg('(-1,0)'::point,'(1,0)'::point) |
| path(polygon) | point | convert to path | path('((0,0),(1,1),(2,0))'::polygon) |
| point(circle) | point | convert to point (center) | point('((0,0),2.0)'::circle) |
| point(lseg,lseg) | point | convert to point (intersection) | point('((-1,0),(1,0))'::lseg, '((-2,-2),(2,2))'::lseg) |
| point(polygon) | point | center of polygon | point('((0,0),(1,1),(2,0))'::polygon) |
| polygon(box) | polygon | convert to polygon with 12 points | polygon('((0,0),(1,1))'::box) |
| polygon(circle) | polygon | convert to 12-point polygon | polygon('((0,0),2.0)'::circle) |
| polygon(npts,circle) | polygon | convert to npts polygon | polygon(12,'((0,0),2.0)'::circle) |
| polygon(path) | polygon | convert to polygon | polygon('((0,0),(1,1),(2,0))'::path) |
Table 5-8. Geometric Upgrade Functions
| Function | Returns | Description | Example |
|---|---|---|---|
| isoldpath(path) | path | test path for pre-v6.1 form | isoldpath('(1,3,0,0,1,1,2,0)'::path) |
| revertpoly(polygon) | polygon | convert pre-v6.1 polygon | revertpoly('((0,0),(1,1),(2,0))'::polygon) |
| upgradepath(path) | path | convert pre-v6.1 path | upgradepath('(1,3,0,0,1,1,2,0)'::path) |
| upgradepoly(polygon) | polygon | convert pre-v6.1 polygon | upgradepoly('(0,1,2,0,1,0)'::polygon) |