Useful places to look for numerical mathematics routine:
========

GSL reference manual:
	http://www.gnu.org/software/gsl/manual/html_node/

GAMS:
	http://gams.nist.gov/

NetLib:
	http://www.netlib.org/


SciLab -- free numerical mathematics package
	http://www.scilab.org


How to use debuggers
========


If you have C or Fortran code under linux, ddd is probably already
installed and lets you easily walk through your code.   The
easiest thing to do is to compile with `-g':

	gfortran -Wall -g foo.f -o foo
or

	gcc -Wall -g foo.c -o foo


The -g flag, pretty universally used with different compilers, turns
on lots of labelling needed by debuggers.  It also disables most
optimizations.

Then run ddd on the executable:

	ddd ./foo

and you'll be thrown into the debugger.   What to do next?

DDD/debugging tutorials:
	http://heather.cs.ucdavis.edu/~matloff/Debug/Debug.pdf
	http://www.gnu.org/manual/ddd/html_mono/ddd.html


Valgrind
========

Valgrind is a programming tool for memory debugging, memory leak finding,
and profiling.

It's essentially a virtual machine which runs your program (you don't
even *need* to compile -g; just whatever executable you have will work
just fine) and can keep track of things like the use of invalid memory
usages, which can be very difficult to find other ways.  In addition it
can do some sorts of profiling.  But beware; because you're essentially
running a simulation of a computer running your program, the program
will routinely run ~20x slower under valgrind than it would normally.
But for finding that hard-to-find memory issue, there's really nothing
else like it.

	http://www.valgrind.org
	http://www.faqs.org/docs/Linux-HOWTO/Valgrind-HOWTO.html