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.
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.
I'm not an Arc anything user but a reasonable workflow would be;
- Ensure an attribute is attached to all points that is unique across the set.
- Copy all points to a working layer. Ensure the unique attribute is carried across to the working points.
- Perform the disperse markers routine.
- Update the source points with the positions of the working points where the unique id matches.
Hope this helps.
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
This can be automated with Arc toolbox and Modelbuilder for different features... or use @scw recommended route.