Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

Does this function allow you to put in an array of points, which may, or may not, be representative of many polygons, and create many polygons from it, or just the one, linked?

share|improve this question
add comment

1 Answer 1

up vote 1 down vote accepted

According to the help file:

Polygons are created around clusters of three or more points within the aggregation distance.

Point aggregation may introduce polygon holes or areas where adjacent polygon boundaries meet at one vertex.

Which would suggest that your aggregation distance will determine whether more than one polygon appears. Note, that an ArcInfo license is required

share|improve this answer
    
I saw this, but it's vague as to whether simply giving a list of points, would build multiple polygons. I also thought the distance would see the polygon sweeping over voids i.e. if you can imagine a dip in the polygon shaped like a 'u', if the distance was over a set amount, the 'u' would be bridged, if under a certain amount, the 'u' would be followed, or replicated, in the polygon. –  Hairy Apr 27 '11 at 12:14
1  
@Hairy You're right; this help page is ghastly. One can "create polygons around" points in so many ways--as buffers, convex hulls, concave hulls, using the points as nodes--that this description is worthless. Such vagueness in the documentation is routine (and has been for decades). The only way to know how any ESRI software really works is to experiment with it. Why not just apply the function to a small point layer of your own to see what it does? –  whuber Apr 27 '11 at 14:04
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.