名称
ST_3DLongestLine — 返回两个几何体之间的 3D 最长直线
大纲
geometry ST_3DLongestLine(geometry g1, geometry g2);
描述
返回两个几何图形之间的 3 维最长直线。 如果有多个线，该函数将返回第一个最长的线。 返回的行以 g1 开始，以 g2 结束。 线的 3D 长度等于 ST_3DMaxDistance 返回的距离。
可用性: 2.0.0
更改：2.2.0 - 如果输入 2 个 2D 几何图形，则返回 2D 点（而不是假设缺失 Z 为 0 的旧行为）。 在 2D 和 3D 情况下，对于缺失的 Z，Z 不再被假定为 0。
该函数支持 3d 并且不会丢失 z-index。
该函数支持多面体曲面。
示例
Longest line between a LineString and a Point, comparing the 3D and 2D results.
Code
SELECT ST_3DLongestLine(line, pt) AS lol3d_line_pt, 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;
栅格输出
lol3d_line_pt | lol2d_line_pt -----------------------------------+---------------------------- LINESTRING(50 75 1000,100 100 30) | LINESTRING(98 190,100 100)
Figure
Longest line between a LineString and a MultiPoint, comparing the 3D and 2D results.
Code
SELECT ST_3DLongestLine(line, pt) AS lol3d_line_pt, 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;
栅格输出
lol3d_line_pt | lol2d_line_pt ---------------------------------+-------------------------- LINESTRING(98 190 1,50 74 1000) | LINESTRING(98 190,50 74)
Figure
Longest line between a Polygon and a MultiLineString, comparing the 3D and 2D results.
Code
SELECT ST_3DLongestLine(poly, mline) AS lol3d, 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;
栅格输出
lol3d | lol2d ------------------------------+-------------------------- LINESTRING(175 150 5,1 10 2) | LINESTRING(175 150,1 10)
Figure