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.

I have a bunch of point layers which often have overlapping features. The disperse markers geoprocessing tool works within a layer but is there a way to do it across more than one layer, so none of the points are overlapping? Using ArcMap 9.3.

share|improve this question
add comment

3 Answers 3

I don't see any direct way, but it'd be easy enough to perform a Merge (docs) on the input data, mapping a field to retain information about the origin layer. In some cases, you may be able to use this merged layer directly, and symbolize the different features within it. Perform disperse markers on the merged set, and use as-is or split on the unique features mapped from fields.

If you only care about making them non-overlapping, and not their specific location, you could displace each layers positions by some systematic amount below the actual mapped resolution of your data, so that they were naturally clustered when mapped. For example, if you had layers A and B, you could make the least two significant figures of A something independent from B:

layer    lat     lon    rule perturbed_lat perturbed_lon
    A   33.0  -120.0  +0.033        33.033      -119.967
    B   33.0  -120.0  +0.011        33.011      -120.989

Now if you perform disperse on one of these layers, the data will already be clustered into distinct areas of the map. You'd have to play with the offset values and figure out an appropriate offset. But this approach would give you a systematic way of preventing collisions between layers.

share|improve this answer
add comment

I'm not an Arc anything user but a reasonable workflow would be;

  1. Ensure an attribute is attached to all points that is unique across the set.
  2. Copy all points to a working layer. Ensure the unique attribute is carried across to the working points.
  3. Perform the disperse markers routine.
  4. Update the source points with the positions of the working points where the unique id matches.

Hope this helps.

share|improve this answer
    
Thanks for the suggestions. I was hoping for a more straightforward way which saved me creating a new layer and symbology. Looks like this is the only option though. Cheers. –  David Aug 24 '10 at 1:37
add comment

Requirements: Arc/Info licence + Maplex Extension and Geodatabase with Cartographic Representations

Displaying Coincident Points http://blogs.esri.com/Support/blogs/mappingcenter/archive/2007/08/27/displaying-coincident-points.aspx

Scatter Markers

http://blogs.esri.com/Support/blogs/mappingcenter/archive/2008/08/01/How-to-scatter-marker-symbols-for-stacked-or-clustered-point-features.aspx

This can be automated with Arc toolbox and Modelbuilder for different features... or use @scw recommended route.

share|improve this answer
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.