Name
ST_3DLongestLine — 返回两个几何之间的3D最长线
Synopsis
geometry ST_3DLongestLine(geometry g1, geometry g2);
描述
返回两个几何图形之间的三维最长直线。如果超过一行，该函数将返回第一行。返回的行从G1开始，以G2结束。线的3D长度等于返回的距离 ST_3DMaxDistance 。
可用性：2.0.0
已更改：2.2.0-如果输入2个2D几何图形，则返回2D点(而不是假设缺少Z的行为为0)。在2D和3D的情况下，对于缺失的Z，不再假定Z为0。
This function supports 3d and will not drop the z-index.
This function supports Polyhedral surfaces.
示例
线串和点--3D和2D最长的线 SELECT ST_AsEWKT(ST_3DLongestLine(line,pt)) AS lol3d_line_pt,
ST_AsEWKT(ST_LongestLine(line,pt)) As lol2d_line_pt
FROM (SELECT 'POINT(100 100 30)'::geometry As pt,
'LINESTRING (20 80 20, 98 190 1, 110 180 3, 50 75 1000)'::geometry As line
) As foo;
lol3d_line_pt | lol2d_line_pt
-----------------------------------+----------------------------
LINESTRING(50 75 1000,100 100 30) | LINESTRING(98 190,100 100)
|
线串和多点--3D和2D最长线 SELECT ST_AsEWKT(ST_3DLongestLine(line,pt)) AS lol3d_line_pt,
ST_AsEWKT(ST_LongestLine(line,pt)) As lol2d_line_pt
FROM (SELECT 'MULTIPOINT(100 100 30, 50 74 1000)'::geometry As pt,
'LINESTRING (20 80 20, 98 190 1, 110 180 3, 50 75 900)'::geometry As line
) As foo;
lol3d_line_pt | lol2d_line_pt
---------------------------------+--------------------------
LINESTRING(98 190 1,50 74 1000) | LINESTRING(98 190,50 74)
|
三维和二维最长线的多重线串和面 SELECT ST_AsEWKT(ST_3DLongestLine(poly, mline)) As lol3d,
ST_AsEWKT(ST_LongestLine(poly, mline)) As lol2d
FROM (SELECT ST_GeomFromEWKT('POLYGON((175 150 5, 20 40 5, 35 45 5, 50 60 5, 100 100 5, 175 150 5))') As poly,
ST_GeomFromEWKT('MULTILINESTRING((175 155 2, 20 40 20, 50 60 -2, 125 100 1, 175 155 1),
(1 10 2, 5 20 1))') As mline ) As foo;
lol3d | lol2d
------------------------------+--------------------------
LINESTRING(175 150 5,1 10 2) | LINESTRING(175 150,1 10)
|