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Is there an easy to calculate the width of a polygon using ArcGIS 9.3.1 or 10? I found some scripts for 9.1 but they will not work. I can use width at widest point, narrowest point, or an average. It does not need to be exact but needs to be somewhat automated because I have a couple hundred to calculate. TIA!

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3 Answers

up vote 1 down vote

This is only a partial answer to your question, but it may be a pointer in the right direction. To clarify, this will will find the width of the polygon envelope at the widest point. Add an attribute with field type double to your feature. Open the field calculator, then click on Advanced. Paste this code into the code block, and set the field that you created equal to Ouput

Dim Output As Double
Dim pPoly as IPolygon
Set pPoly = [Shape]
Dim pEnve as IEnvelope
Set pEnve = pPoly.Envelope
Output = pEnve.Width

Works in 9.3.1. Originally posted here.

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This seems to be the width of the envelope: that does not seem to be what the OP is asking. – whuber♦ Oct 25 '10 at 15:07
I edited my answer to clarify that, thanks for pointing it out. The original question did say that it did not need to be exact, so the width of the envelope may be sufficient. – Zachary Oct 25 '10 at 15:42
The width of the envelope is about as inexact as one can get, unfortunately. For instance, when the feature is aligned with its width in a vertical direction, the "width" of the envelope actually estimates the feature's length. Your idea of exploiting the envelope's width has been used in code that systematically rotates the feature in a search for the minimum envelope width: in many cases this has a legitimate claim to be a reasonable estimate of width. I believe Dan Patterson has a contribution of this nature on ArcScripts. – whuber♦ Oct 25 '10 at 16:05
up vote 3 down vote

The width of a minimum-area bounding rectangle provides one solution. Calculate this as the minimum of the "length" and "width" of the rectangle.

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up vote 1 down vote

The version for 9.3.x and 10 is posted here http://resources.arcgis.com/gallery/file/geoprocessing/details?entryID=3D230972-1422-2418-34A5-2F3FFF97C238 There are also a variety of other "containers" that can be derived (MABR, envelope, Min area circle, convex hull) and tables will contain attribute information depending upon the contain chosen

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Welcome, Dan! If you haven't seen it yet, check out recent discussions on the 'meta' site. – whuber♦ Oct 27 '10 at 21:47

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