Notes on creating new map databases.

1) See the references:
Richard A. Becker, and Allan R. Wilks,
"Maps in S",
emph{AT\&T Bell Laboratories Statistics Research Report [93.2], 1993.}

Richard A. Becker, and Allan R. Wilks,
"Constructing a Geographical Database",
\emph{AT\&T Bell Laboratories Statistics Research Report [95.2], 1995.}

2) After the .line .gon and .n ascii files have been created or modified,
rerun ./getstats.sh to generate the appropriate .linestats and .gonstats
files.

3) Edit the Makefiles to add the appropriate names to the lists of
.G, .L and .N files

4) Create the ../data/<mapname>.r file consisting of the assignment
'<mapname>MapEnv <- "R_MAP_DATA_DIR"'.  This sets the name of the
environment variable, created at load time (see ../R/zzz.R), that
specifies the location of the binary data files for this collection
of maps. [The mapdata package uses a different environment variable.]

Ray Brownrigg
21 March 2009
