Multipart Polygons

[R. Morse]

Luke,

Yes, I'd updated those attributes but still had gotten extra area.  Since
then I found the overlapping polygons, more by luck than by process
though, which still leaves me in need of a way to detect them in advance.

Rick

On Wed, 12 Sep 2001, Luke W Rogers wrote:

> And you have updated the Area attribute using the Calculate Area, Perimeter,
> Length tool in XTools?
>
> -Luke
>
> -----Original Message-----
> From: UW-GIS-L-owner at u.washington.edu
> [mailto:UW-GIS-L-owner at u.washington.edu]On Behalf Of R. Morse
> Sent: Wednesday, September 12, 2001 2:13 PM
> To: UW - GIS Discussion & Support
> Subject: Multipart Polygons
>
>
>
> I've been trying to determine why two shapefiles, that are each the result
> of multiple overlays, don't have the same total area, as they should.
> Both have been clipped with the same polygon so there is no overlap or
> shortfall at the edge of the layers. My guess is that multipart polygons
> in early layers created overlapping polygons when the final layers were
> produced, and these overlapping polygons are causing some area to be
> double counted.  Are there ways to locate these areas of overlap in the
> latter product and to identify multipart polygons before the overlay
> process? One thought has been to generate a centroid for each polygon with
> the hope of locating overlaps where identical centroids coexisted, but
> have had no luck with that yet.
>
>
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>

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