Customizing Maps in R: spplot() and latticeExtra functions

I recently noticed the new latticeExtra page on R-forge, which contains many very interesting demos of new lattice-related functionality. There are strong opinions about the “best” graphics system in R (base graphics, grid graphics, lattice, ggplot, etc.)– I tend to use base graphics for simple figures and lattice for depicting multivariate or structured data. The sp package defines classes for storing spatial data in R, and contains several useful plotting methods such as the lattice-based spplot(). This function, and back-end helper functions, provide a generalized framework for plotting many kinds of spatial data. However, sometimes with great abstraction comes great ambiguity– many of the arguments that would otherwise allow fine tuning of the figure are buried in documentation for lattice functions. Examples are more fun than links to documentation, so I put together a couple of them below. They describe several strategies for placing and adjusting map legends– either automatically, or manually added with the update() function. The last example demonstrates an approach for over-plotting 2 rasters. All of the examples are based on the meuse data set, from the gstat package.

Extended spplot() examples

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