[R] Installing rgl package under Ubuntu

[Ivailo Stoyanov]

Dear Rexperts,

lately I'm having troubles installing the rgl package via
install.packages("rgl", dependencies=T) in the R 2.4.0 backport running
under Ubuntu 6.06 LTS. I get the following error messages, despite
having installed libx11-dev (as recommended in a similar post about SUSE
10.1):

trying URL 'http://cran.xedio.de/src/contrib/rgl_0.68.tar.gz'
Content type 'application/x-gzip' length 701566 bytes
opened URL
==================================================
downloaded 685Kb

* Installing *source* package 'rgl' ...
checking for gcc... gcc
checking for C compiler default output file name... a.out
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking for suffix of executables...
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ANSI C... none needed
checking how to run the C preprocessor... gcc -E
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/Rtmpni68vG/downloaded_packages
Warning message:
installation of package 'rgl' had non-zero exit status in:
install.packages("rgl", dependencies = T)
+---------------------------------------+

Has anyone experienced a similar problem, and what would be the
resolution of the "X11 not found" message?

Thank you in advance!

Greets,
Ivailo