tensor algebra

[Brian Gough]

Jordi Burguet Castell writes:
 > I have written some software to do simple tensor algebra, that you
 > may want for the GSL. For the moment it is only complete in its C++
 > implementation, though.  It is not finished in its C & GSL-style
 > incarnation, and maybe someone out there would like to finish it
 > before I do it myself. More on that at the end,

Thanks for the code.  It looks interesting.  I will give some thought
to how tensors should interact with the rest of GSL.