Re: [postgis-users] Intersection of three polygons

Hi Saranya, 2017-02-20 5:57 GMT+01:00 Saranya Kuniyil : > >> Hi all, >> I am new to postgis and I need to find intersection of three polygons. >> In my table named "mytable" contains large no of polygon coordinates and >> grouped into three categories by adding a field

Re: [postgis-users] Geography point to polygon st_distance for a polygon crossing the equator

Thanks Paul, I get it now. So I guess, it all comes from the fact that an arc is defined as the shortest path between 2 points which in the geometry case is a straight line and in the geography case is a great circle. This also mean that "the polygon I had in mind" cannot be defined as a geography

Re: [postgis-users] Intersection of three polygons

For example: POLYGON((0 0,0 1,1 1,1 0,0 0)) filename as part1 POLYGON((0 0,0 3,3 3,3 0,0 0)) filename as part1 POLYGON((0 0,0 2,2 2,2 0,0 0)) filename as part2 POLYGON((0 0,0 5,5 5,5 0,0 0)) filename as part2 POLYGON((0 0,0 3,3 3,3 0,0 0)) filename as part3 POLYGON((0 0,0 4,4 4,4 0,0 0))

Re: [postgis-users] Intersection of three polygons

Hey, sorry to say it's very difficult to understand what you want to do. Please either do a schema or a precise description (with math: you have setA, set B, setC , and you want to find ...). Cheers, Rémi-C 2017-02-20 5:57 GMT+01:00 Saranya Kuniyil : > Hi all, > I am new