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Subject: [ggl] point on the border and within ?
From: Mateusz Loskot (mateusz)
Date: 2011-10-05 13:42:55

On 05/10/11 15:33, Adam Wulkiewicz wrote:
> 2011/10/5 Aleksandar Babic<aleksandarb_at_[hidden]>
>> Hei, I have the following problem - detecting point on the border
>> of ring, The code is like this: [...] I'm always getting NO. Am I
>> doing something wrong .. or this is a bug?
> Hi,
> within() returns false for borders.

There are many subtle differences between those predicates.
Here is a good summary of them:

and PostGIS documentation is a good source of graphical examples:

Also, I think it's better to speak of boundaries, not borders.

Best regards,

Mateusz Loskot,
Charter Member of OSGeo,
Member of ACCU,

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