[postgis-users] ST_Contains vs. ST_Within

[cyw at dls.net]

You are right. I misread.
Thanks.
cyw
----- Original Message ----- 
From: "Kevin Neufeld" <kneufeld at refractions.net>
To: "PostGIS Users Discussion" <postgis-users at postgis.refractions.net>
Sent: Thursday, September 04, 2008 9:51 PM
Subject: Re: [postgis-users] ST_Contains vs. ST_Within


> They are indeed inverses.  Are both your geometries valid?  Can you 
> provide a test case?
> 
> -- Kevin
> 
> cyw at dls.net wrote:
>> Thanks. But the two behave differently.
>>
>> I tried both with the same data (see below) , Within returned more 
>> records.
>>
>> select * into dupage  from maj where Contains((select the_geom from 
>> city where area_id=21002891), the_geom)
>>
>> select * into dupage  from maj where Within(the_geom, (select the_geom 
>> from city where area_id=21002891) )
>>
>>
>> ----- Original Message ----- From: "Paul Ramsey" 
>> <pramsey at cleverelephant.ca>
>> To: "PostGIS Users Discussion" <postgis-users at postgis.refractions.net>
>> Sent: Thursday, September 04, 2008 5:59 PM
>> Subject: Re: [postgis-users] ST_Contains vs. ST_Within
>>
>>
>>> They in inverses.
>>>
>>> ST_Contains(A,B) <=> ST_Within(B,A)
>>>
>>> P.
>>>
>>> On Thu, Sep 4, 2008 at 3:49 PM,  <cyw at dls.net> wrote:
>>>> What are the difeerences between these two functions?
>>>> Thanks.
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