Name
ST_DistanceCPA — 返回两条轨迹的最近接近点之间的距离。
Synopsis
float8 ST_DistanceCPA(geometry track1, geometry track2);
描述
返回两条轨迹在它们最接近的相交点处的距离（在二维空间中）。
输入必须是经 ST_IsValidTrajectory 检查的有效轨迹。 如果轨迹在其 M 范围内不重叠，则返回 Null。
可用性：2.2.0
该函数支持 3d 并且不会丢失 z-index。
示例
-- Return the minimum distance of two objects moving between 10:00 and 11:00
WITH inp AS ( SELECT
ST_AddMeasure('LINESTRING Z (0 0 0, 10 0 5)'::geometry,
extract(epoch from '2015-05-26 10:00'::timestamptz),
extract(epoch from '2015-05-26 11:00'::timestamptz)
) a,
ST_AddMeasure('LINESTRING Z (0 2 10, 12 1 2)'::geometry,
extract(epoch from '2015-05-26 10:00'::timestamptz),
extract(epoch from '2015-05-26 11:00'::timestamptz)
) b
)
SELECT ST_DistanceCPA(a,b) distance FROM inp;
distance
-------------------
1.965214737762069