Multivariate Numerical Integration

[John.Cagnol@devinci.fr]

Dear All,

If I understand correctly, multivariate integration routines have yet
to be be implemented in gsl.  Is there a project in progress?  

May be functions of two variables and a simple domains would be a good
start.  I believe we would need two new types, one for the domains and
one for functions of several variables.

I am looking forward to hearing your reactions.

John.