computing R-squared with gsl_multifit

[Brian Gough]

At Tue, 25 Sep 2007 13:46:28 -0600,
Patrick Alken wrote:
>   Computing the value would require adding about 4-5 lines of
> code and it can be computed at the same time as chisq so there
> doesn't have to be an extra loop added in.

Hello,

I think I'd prefer not to have results passed back through the
workspace, it's not really part of the design -- a separate function
is better, as for the correlation coefficient.

A question: is the formula the same for both weighted and unweighted
fits?

-- 
Brian Gough