Does ST_SimplifyPreserveTopology preserve "contains" property

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Does ST_SimplifyPreserveTopology preserve "contains" property

Igor Stassiy
Hello,

does any postgis implementation of ST_SimplifyPreserveTopology preserve
"contains" property for polygons and multilines, that is, if I have a (Multi)Polygon Parent and a (Multi)Linestring/(Multi)Polygon Child s.t. 
ST_Contains(Parent, Child) holds, will ST_Contains(ST_SimplifyPreserveTopology(Parent), ST_SimplifyPreserveTopology(Child)) also hold?

Here I assume that the threshold for simplifying is the same for both Child and Parent.

Thank you,
Igor

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Re: Does ST_SimplifyPreserveTopology preserve "contains" property

Paul Ramsey
No, it preserves internal topology, not relative topology.

On Thu, Mar 26, 2015 at 9:59 AM, Igor Stassiy <[hidden email]> wrote:

> Hello,
>
> does any postgis implementation of ST_SimplifyPreserveTopology preserve
> "contains" property for polygons and multilines, that is, if I have a
> (Multi)Polygon Parent and a (Multi)Linestring/(Multi)Polygon Child s.t.
> ST_Contains(Parent, Child) holds, will
> ST_Contains(ST_SimplifyPreserveTopology(Parent),
> ST_SimplifyPreserveTopology(Child)) also hold?
>
> Here I assume that the threshold for simplifying is the same for both Child
> and Parent.
>
> Thank you,
> Igor
>
> _______________________________________________
> postgis-users mailing list
> [hidden email]
> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
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