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Geometric Functions
The geometric types point, box, lseg, line, path, polygon, and
circle have a large set of native support functions.
Table 5-12. Geometric Functions
Function Returns Description Example area(object) float8 area of item area(box '((0,0),(1,1))') box(box,box) box intersection box box(box '((0,0),(1,1))',box '((0.5,0.5),(2,2))') center(object) point center of item center(box '((0,0),(1,2))') diameter(circle) float8 diameter of circle diameter(circle '((0,0),2.0)') height(box) float8 vertical size of box height(box '((0,0),(1,1))') isclosed(path) bool a closed path? isclosed(path '((0,0),(1,1),(2,0))') isopen(path) bool an open path? isopen(path '[(0,0),(1,1),(2,0)]') length(object) float8 length of item length(path '((-1,0),(1,0))') pclose(path) path convert path to closed popen(path '[(0,0),(1,1),(2,0)]') npoint(path) int4 number of points npoints(path '[(0,0),(1,1),(2,0)]') popen(path) path convert path to open path popen(path '((0,0),(1,1),(2,0))') radius(circle) float8 radius of circle radius(circle '((0,0),2.0)') width(box) float8 horizontal size width(box '((0,0),(1,1))')
Table 5-13. Geometric Type Conversion Functions
Function Returns Description Example box(circle) box circle to box box('((0,0),2.0)'::circle) box(point,point) box points to box box('(0,0)'::point,'(1,1)'::point) box(polygon) box polygon to box box('((0,0),(1,1),(2,0))'::polygon) circle(box) circle to circle circle('((0,0),(1,1))'::box) circle(point,float8) circle point to circle circle('(0,0)'::point,2.0) lseg(box) lseg box diagonal to lseg lseg('((-1,0),(1,0))'::box) lseg(point,point) lseg points to lseg lseg('(-1,0)'::point,'(1,0)'::point) path(polygon) point polygon to path path('((0,0),(1,1),(2,0))'::polygon) point(circle) point center point('((0,0),2.0)'::circle) point(lseg,lseg) point intersection point('((-1,0),(1,0))'::lseg, '((-2,-2),(2,2))'::lseg) point(polygon) point center point('((0,0),(1,1),(2,0))'::polygon) polygon(box) polygon 12 point polygon polygon('((0,0),(1,1))'::box) polygon(circle) polygon 12-point polygon polygon('((0,0),2.0)'::circle) polygon(npts polygon npts polygon(12,'((0,0),2.0)'::circle) polygon(path) polygon path to polygon polygon('((0,0),(1,1),(2,0))'::path)
Table 5-14. 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 to pre-v6.1 revertpoly('((0,0),(1,1),(2,0))'::polygon) upgradepath(path) path to pre-v6.1 upgradepath('(1,3,0,0,1,1,2,0)'::path) upgradepoly(polygon) polygon to pre-v6.1 upgradepoly('(0,1,2,0,1,0)'::polygon)
