Hello, I am working with a 3D grid of a small number of discrete values, where the grid is Cartesian (cell borders are orthogonal) but has irregular cell width/length/height. I would like to make plots of 2D cross sections through the grid. I want to show the exact outlines of contiguous groups of like-valued cells. A couple of years ago Roger Bivand pointed out how to do this in 2D, using Polygon(), unionSpatialPolygons(), and other functions. Is there a way to do this with a cross section taken through the 3D grid in one of the principal directions? I don't see mention or examples of 3D polygons. Or do I need to derive the polygons and union them separately for each cross section?
Also, is there an easy way to search the R-sig-geo archives? Thanks, Scott Waichler Pacific Northwest National Laboratory [email protected] _______________________________________________ R-sig-Geo mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-geo
