Description
Fields is for curve, surface and function
fitting with an emphasis on splines, spatial data and spatial
statistics. The major methods include cubic, robust, and thin plate
splines, and Kriging for large data sets. The splines and Kriging
methods are supporting by functions that can determine the smoothing
parameter (nugget and sill variance) by cross validation and also by
restricted maximum likelihood. A major feature is that any
covariance function implemented in R with the fields interface can be
used for spatial prediction. Some tailored optimization functions are
supplied for find the MLEs for the Matern family of covariances.
There are also many useful functions for plotting and working with
spatial data as images. This package also contains an implementation
of a sparse matrix methods for large data sets and currently requires
the sparse matrix (spam) package for testing (but not for the
standard spatial functions.) Use help(fields) to get started and for
an overview. The fields source code is heavily commented and should
provide useful explanation of numerical details in addition to the
manual pages.