[R] Pkg rgl: installation fails because of x11

[Matthieu Stigler]

Hello

Im trying to install package rgl in a freshly installed Ubuntu 8.04
system. I have a problem (actually is has been reported three times on
the R-list but the answers were too complicated for me) when
installing:

configure: using libpng dynamic linkage
checking for X... no
configure: error: X11 not found but required, configure aborted.
ERROR: configuration failed for package 'rgl'
** Removing '/usr/local/lib/R/site-library/rgl'

The downloaded packages are in
	/tmp/RtmpcnTzdW/downloaded_packages
Warning message:
In install.packages("rgl", dep = TRUE) :
  installation of package 'rgl' had non-zero exit status


I see two potential explanations:
-to use rgl I should install some OpenGl package... is it right? which one then?
-rgl only needs x11 but does not find it. I see actually that there is
no x11 in /usr/ but X11R6 does the problem come from that?

PS: Im cross posting on R and rgl list

Thank you for your help!