Re: Parallel computing abilitites in GSL?

[Brian Gough <bjg at network-theory dot co dot uk>]

Hossein S. Zadeh writes:
 > I agree and disagree!! I agree that a generalised kind of parallelism is
 > well outside the scope of GSL. But algorithms like Simulated Annealing can
 > have a parameter to specify how many child threads to spawn. On a
 > multi-cpu system this could help a lot. And even though this doesn't help
 > with load distribution over a cluster, it makes it easier to incorporate
 > it in things like PVM. (I haven't actually used Simulated Annealing in
 > GSL, so this might already be provided??)

For algorithms like simulated annealing or monte carlo integration I
think the user could start up each thread from their application.
However, what GSL certainly needs for parallel codes is improvement of
the RNGs to support a larger seed space.  The current 32-bit seed is
inadequate for parallel programs.   

What's probably needed is an extra method for each generator which
accepts a arbitrary-sized array of seed bits, and hashes it up or down
in size to fit each generator. This could be used to provide a two
argument seed function gsl_rng_seed2 (thread_id,seed).

Brian