I have ARC 10.2.1.
I have a shapefile of polygons, and the I need the maximum N / S / E / W points for each polygon (not the centre point)
Is there a way to do this?
(I can use the tools etc, but have no knowledge of scripts or anything like that, so I would need some pretty basic instructions if that's what's required)
(Geometric attributes / extent only gives 2 max/min extents which do not reflect the actual shape of the polygon, not all 4)
Hi, same reply, but I couldn't figure out how to turn off "assumed answered"
I really appreciate your help, and I may have a fundamental misunderstanding, and am happy to be corrected, but it seems that no - it doesn't.
If you assume, for the sake of argument, your shape is diamond, it gives you the bottom left coordinate and the top right coordinate as if someone had drawn a square around your shape, and given you only those two points. So it doesn't give all 4 points, and the 2 points it does give are not actually in the polygon?
A quick option is to convert the polygon to points, calculate the X/Y coordinates for the points in new fields and with a Select by Attributes query get the max/min from the X/Y field values and use that as your maximum extent points.
Here is the SQL expression to get the max/min in a field, which should be used in the Select by Attributes query box:
X = (SELECT max( X ) FROM MyPolygonPoints)
X = (SELECT min( X ) FROM MyPolygonPoints)
You could then convert this process to a model if you have multiple polygons.
That sounds like exactly what I want - I have 430 polygons, so a model sounds like the way to go. As I've never used SQL or models before, can you point me to a 'Dummies guide to models?" link
Thanks but as above, I need points that are part of the polygon, not the points of a container which (given the irregular shapes of my polygons) are not actually located within the shape