Name
GetEdgeByPoint — Finds the edge-id of an edge that intersects a given point.
Synopsis
bigint GetEdgeByPoint(varchar atopology, geometry apoint, float8 tol1);
Descrição
Retrieves the id of an edge that intersects a Point.
A função retorna uma inteireza (id-limite) dada uma topologia, um PONTO e uma tolerância. Se tolerância = 0, o ponto tem que intersectar o limite.
If apoint doesn't intersect an edge, returns 0 (zero).
If use tolerance > 0 and there is more than one edge near the point then an exception is thrown.
![[Note]](../images/note.png)
|
|
|
Se tolerância = 0, a função usa ST_Intersects, senão usa ST_DWithin. |
Desempenhado pelo módulo GEOS.
Disponibilidade: 2.0.0
Exemplos
Estes exemplos utilizam limites que criamos em
SELECT topology.GetEdgeByPoint('ma_topo',geom, 1) As with1mtol, topology.GetEdgeByPoint('ma_topo',geom,0) As withnotol
FROM ST_GeomFromEWKT('SRID=26986;POINT(227622.6 893843)') As geom;
with1mtol | withnotol
-----------+-----------
2 | 0
SELECT topology.GetEdgeByPoint('ma_topo',geom, 1) As nearnode
FROM ST_GeomFromEWKT('SRID=26986;POINT(227591.9 893900.4)') As geom;
-- get error --
ERROR: Two or more edges found