ST_CPAWithin
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Name

ST_CPAWithin — 测试两条轨迹的最近接近点是否在指定距离内。

Synopsis

boolean ST_CPAWithin(geometry track1, geometry track2, float8 dist);

描述

测试两个移动物体是否曾经比指定距离更近。

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 False。

可用性：2.2.0

该函数支持 3d 并且不会丢失 z-index。

示例

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_CPAWithin(a,b,2), ST_DistanceCPA(a,b) distance FROM inp;

 st_cpawithin |     distance
--------------+------------------
 t            | 1.96521473776207