Representing data

ArcMap and its extensions provide a broad range of methods to visualize data, some involving transformations and manipulations. I'm exploring the functionality for the first time, so part of what I'm doing is inordinately clumsy. I don't know any more efficient way of getting better than to try to keep track of my progress.

I made a .shp file of county centroids, using an extension for ArcView 3.2, and then used that as a basis for this surface:

While this captures the essences of hills and valleys, there are problems that need to find solutions, notably the part played by the water... and by Canada and Mexico.

From the Spatial Analyst Interpolate to Raster ==> Inverse Distance Weighted

(I made R:/global/uscounties/ginicentroid.shp to contain BOTH the Gini data and the points...)

a Spline of ginicentroid produces garbage; a Kriging works nicely (usgini8v.mxd)