[postgis-users] Area calculation oh two polygon that they are overlapping

[Guido Lemoine]

Your multipolygon is simply two rings of 3 by 3. Defining them
as multipolygon does do nothing for intersection, so the area is 18
(which is 9 + 9). You need to look up what intersection means.
For me, the intersection of the 2 polygons is the common area,
which is 4.

GL

olivier.amram at free.fr wrote:
> Hi,
>
> I'd like to compute the total area of polygon that intersects with another
> polygon
>
> Polygon(0 0,0 3,3 3,3 0,0 0)
> Polygon(1 1,4 1,4 4,1 4,1 1)
>
> The total area is 14 but I don't find a solution to compute this value.
>
> e.g. SELECT Area(GeomFromText('MultiPolygon( ((0 0,0 3,3 3,3 0,0 0)),((1 1,1 4,4
> 4,4 1,1 1)))')) --> 18
>
> Have you any idea ?
>
> Thank,
>
> Olivier.
>
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>
>   

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Guido Lemoine
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