ACS Data Users Group

Does anybody have a resource at the tip of their fingers that would have PUMA adjacency structure? I.e., which PUMA is a neighbor to another PUMA.

On TIGERweb you can turn on the PUMA layer and see what PUMAs are around the area you are looking at. Not sure if that is what you were wanting or not.

Thanks, Barbara -- I need the full 2351 x 2351 matrix... I can't be doing those PUMAs one by one, I need to read the whole file and process it.

I believe that there are packages in R and in Stata that will produce in adjacency matrix from a GIS shape file

Thanks, Matthew -- do you mean like this -- stackoverflow.com/.../874882

I'm not as familiar with the R packages, but I have used shp2dta and spmap in Stata.

Matthew, I see. I don't think they produce the adjacency matrix. But I guess I can ask Kevin Crow who produced them.

If you have the layer and you have access to ArcGIS, you should be able to produce such a matrix using the Polygon Neighbors tool. I recently did this for tracts in LA county. The output is "long" in the sense that you'd have multiple rows for "source_FIPS" with a unique "neighbor_FIPS" - you also get the length of the shared border and whether or not there's a "node" (corner adjacency).

Should have stated this above: the Polygon Neighbors tool is under "Analysis Tools" -> "Proximity" in ArcGIS Toolbox.