[postgis-users] Re: touches() not returning correct values, maybe?

[Paul Ramsey]

Touches() is only true if the exteriors interact and the interiors do 
not. If your adjacent polygons overlap slightly, then they do not just 
touch.

P.

Jeff D. Hamann wrote:
> This seems to remedy this situation.
> 
> select
>   t1.gid as gid,
>   t2.gid as adj_gid
>  from
>   stands t1,
>   stands t2
>  where
>   intersects( t1.boundary, t2.boundary ) AND
>    t1.boundary && t2.boundary and
>   Equals( t1.boundary, t2.boundary ) is FALSE
> order by
> 	t1.gid,
> 	t2.gid;
> 
> So why is this different than
> 
> select
>   t1.gid as gid,
>   t2.gid as adj_gid
>  from
>   stands t1,
>   stands t2
>  where
>   touches( t1.boundary, t2.boundary ) AND
>    t1.boundary && t2.boundary and
> order by
> 	t1.gid,
> 	t2.gid;
> 
> Jeff.
>