The comprehensive R archive (CRAN)
has a bunch of very useful libraries. You can install a library from
within R using the `install.packages()` function. Among the
useful libraries I use are:

- maps: allows you to make maps of the world, the US, and smaller areas
- mapproj: allows you to do cartographic projections
- fields: lots of useful functions for spatial data, including kriging and thin-plate splines
- nlme: linear and non-linear mixed effects models
- mgcv: provides a
`gam()`function that allows you to do multivariate non-parametric regression (i.e., non-additive modelling) using multiple penalty optimization - this is a much more flexible model that the`gam()`in Splus that does additive modelling - ts: time series stuff

To load a library automatically when you begin your R session, include
the line
`library( lib_name)`

in your .