[R-sig-Geo] rgeos, gpclib and polygon plotting

[Elena]

Dear all,

I recently switched to Ubuntu and have also just started to explore R as
GIS.I am loading some packages in R to plot a shapefile (rgdal,
shapefiles, maptools), and I have stumbled upon rgeos and gpclib. I get
the message that I need geos 3.2.2 or newer, with the tip about
gpclibPermit(). It turns out I do not have a license for gpclib.  My
first question is if there is a way around this, or do I have to open R
from Windows to get newer versions of geos?

The second question: I got four xyp files compiling information from
many bln polygons originally made in Surfer, but only one of these xyp
files has four variables (I assume the fourth is the sequence number).
What kind of object should these xyp files be, and what function should
I use to plot them?

And the third question: I saved the only xyp file with four columns as
csv, imported it into R, added column names so it could pass as a
PolySet and plotted it with the package PBSmapping. I get several diagonal
lines across the map. Are they due to the fact that the sequence skips a number at the start/end
of each polygon? Or is it because the polygons are not properly closed?

Thanks for your help!

Elena