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Multiple values per polygon

December 10 2009 | 2 comments
Categories: Map Data

In my map, I am trying to show the numbers of deeds with race restrictions, numbers of deeds without race restrictions, and numbers of deeds where the information is not know, by the Public Land Survey System section. I've created three different layers to represent each of these features. The problem is that that, if I use graduated or proportional symbols, they are all placed in the center of the section, with the larger ones overlapping the smaller ones.

In one of the forums, at http://forums.esri.com/Thread.asp?c=93&f=988&t=177757, the author (in 2006) wrote:

"One thing you could do is create a grid of square polygons (each polygon being the size of the area you'd like a label to appear in) that covers the area of your other polygons. GridPolys1

Then use the Clip tool to clip the square polygons to match your original polygons. GridPolys2

Then use a Spatial Join (Intersect) so that each square polygon gets the attributes of your original polygon. GridPolys3

Now you can label the map using the attributes from GridPolys3"

Would you be able to tell me how I do the first step -- "creating a grid of square polygons"? I have the book _GIS Tutorial Updated for ArcGIS 9.2_, but have only gotten through the chapter on "Geodatabases". Is there a section later in the book that would explain how to do this, or something in the ArcView 9.3 Help that would explain this?

Thanks!

Mapping Center Answer:

You can use the Create Fishnet tool in ArcToolbox to create a grid of regular polygons.

Use 'Feature To Polygon' to create polygons posted by Cory Eicher on Feb 22 2010 6:21AM
Hi

You need to use 'Feature To Polygon' to create polygons. Create Fishnet creates a line feature class. I am using ArcGIS 9.3.1.

Also, the link above goes to a "how does it work" topic instead of the tool help, which explains that you need to use this additional tool.

http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?id=1782&pid=1777&topicname=Create_Fishnet_%28Data_Management%29

Thanks!

-Cory
Multiple values per polygon posted by Wendy Plotkin on Feb 22 2010 8:48AM
Thanks, Cory.

I just purchased a single license version of ArcGis 9.3.1 and Maplex. I am going to have to do a little catching up in my training, and will then try what you suggested. I am also hoping that Maplex will allow me to solve the problem in an easier way.

Best,
Wendy

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