My previous announcement of a fix was premature. The problem is now
really solved.
Some time ago I mentioned difficulty using the latest additions to David
Young's 'popvision' extension to Pop11.
He had introduced Pop11 libraries that invoked the powerful BLAS and
LAPACK fortran libraries. This allowed a wide range of mathematical
procedures to be conveniently accessed interactively in pop11, in a
similar way to Matlab, though with the extra generality of the pop11
language (which is similar in power to Lisp.)
However, some of the LAPACK procedures failed to access BLAS procedures,
causing 'undefined symbol' errors.
Various people make suggestions, and then I thought the problem had been
solved by getting new libraries. I wrote, prematurely, on Thu, 23 Dec
2004:
> This problem is now solved using the latest lapack and blas rpms.
The problem disappeared after installing new versions of blas, and
lapack along with blas-devel, lapack-devel, and libg2c libraries.
Somehow that enabled me to use David's packages.
However, thanks to further investigations and help from David Young and
Jeff Best I found that there was a bug in the linux version of Poplog's
mechanisms for linking in dynamic libraries: a bit was not set in one
of the control flags which would have made symbols 'global'. This bit
was set properly in Solaris poplog which is why the Lapack extensions
had worked on Suns.
After linux poplog was rebuilt with the dynamic linking bug fixed, it
turned out that the new blas and lapack libraries were not required
after all, since the lapack extension to pop11 worked on machines
running Redhat 8 and 9 that had not had the latest blas and lapack
libraries installed.
I.e. installing the new libraries (including the -devel versions)
was merely a 'workaround' rather than a fix to the basic cause of the
problem.
The latest version of linux poplog, incorporating this dynamic linking
fix can now be fetched from
http://www.cs.bham.ac.uk/research/poplog/freepoplog.html
http://www.cs.bham.ac.uk/research/poplog/bham-linux-poplog.tar.gz
The 'News' section of the former file mentiones other recent
developments, including reduction in size of the bham-linux-poplog tar
file from about 21 Mbytes to about 19Mbytes, and provision of a script
for checking a PC linux system to see if meets the main requirements
for installing Poplog. (If run as root it can install missing symbolic
links in /usr/X11R6/lib/ )
Apologies for the red-herrings and premature announcement!
Thanks to all who offered suggestions regarding the dynamic linking
problem and seasonal greetings.
Aaron
====
Aaron Sloman, ( http://www.cs.bham.ac.uk/~axs/ )
PAPERS: http://www.cs.bham.ac.uk/research/cogaff/ (also talks in /talks )
FREE BOOK: http://www.cs.bham.ac.uk/research/cogaff/crp/
FREE TOOLS: http://www.cs.bham.ac.uk/research/poplog/packages/simagent.html
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