Hello,

I'm reporting a recent experience in case there is someone else out 
there wanting to try out octave's fltk alternative to gnuplot under 
RHEL/Centos/SL.  I'm running SL 6.5, and the octave-3.4.3-1.el6.x86_64 
available from EPEL only offers gnuplot, although 
/usr/share/doc/octave-3.4.3/NEWS announces the presence of fltk.

While I was at it, I thought I would get a more recent octave than 3.4 
and downloaded octave-3.8.1.tar.gz from the octave website. 
../configure reported some missing libraries that yum located in various 
devel packages, but even after installing the packages I continued to 
get a report that OpenGL was missing and that native graphics would 
therefore be unavailable.

I eventually spotted a "-lGL not found" line in config.log, in spite of 
the fact that /usr/lib64/libGL.so was present, having been provided by 
mesa-libGL-devel.  The problem was that it was a broken symbolic link to 
libGL.so.1.2.0, which rpm -ql says mesa-libGL should provide.  But what 
I actually had was libGL.so.1.2 instead.  Making libGL.so point to that 
fixed the problem and octave now offers a choice of gnuplot and fltk 
graphics toolkits.  (It also offers a matlab-like gui, which, as they 
tell you, is not yet ready for everyday use.)

My guess is that the library name mixup is more likely to be a RedHat 
problem than a Scientific Linux one, so I have reported it on their 
bugzilla.

Stephen Isard