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
------------------
 1.96036833151395

相关信息

ST_IsValidTrajectory, ST_ClosestPointOfApproach, ST_AddMeasure, |=|