[R] map("state" ...) Is the USA cracking up?

[John P. Burkett]

Running R version 2.6.1 under Linux, I'm trying to use the maps and 
mapdata packages and the state database to produce a thematic map of the 
USA.  My problem is that cracks (white spaces) appear between some 
states--e.g. between Colorado and Utah and between Michigan and Indiana. 
The resulting visual impression is that the country is breaking up. 
This occurs in all the projections I have tried: albers, mercator, 
sinusoidal.  An example of a command producing this effect is the following:
map("state", regions=names48, projection="albers", par=c(36, 53), 
fill=T, col=rgb(red, green, blue, maxColorValue=255))
Suggests for filling the cracks would be very welcome.
-John

-- 
John P. Burkett
Department of Environmental and Natural Resource Economics
and Department of Economics
University of Rhode Island
Kingston, RI 02881-0808
USA

phone (401) 874-9195