Math::RungeKutta.pm

This module offers algorithms for the numerical integration of
simultaneous differential equations of the form  dY/dt = F(t,Y)
where Y is an array of variables whose initial values Y(0) are
known, and F is a function known from the dynamics of the problem.

Three main algorithms are offered.  rk2 is Heun's 2nd-order Runge-Kutta
algorithm, which is relatively imprecise, but does have a large range
of stability which might be useful in some problems.  rk4 is Merson's
4th-order Runge-Kutta algorithm, which should be the normal choice in
situations where the step-size must be specified.  rk_auto uses Merson's
4th-order Runge-Kutta algorithm to adjust the step-size automatically
to achieve a specified precision; this saves much fiddling around
trying to choose a good step-size, and much CPU time by automatically
increasing the step-size when the solution is changing only slowly.

Perl is not the right language for high-end numerical integration like
global weather simulation, colliding galaxies and so on, but as Gear says,
"Many equations that are solved on digital computers can be classified as
trivial by the fact that even with an inefficient method of solution,
little computer time is used. Economics then dictates that the best method
is the one that minimises the human time of preparation of the program."

This module should be helpful in solving systems of differential
equations which arise within a Perl context, such as economic, financial,
demographic or ecological modelling, mechanical or process dynamics, etc.

To install:
   perl Install

that's all ! or you can still do it the old way ...
   perl Makefile.PL
   make
   make test
   make install

For up-to-date source, see http://search.cpan.org/~pjb

Peter J Billam    www.pjb.com.au   www.pjb.com.au/comp/contact.html