[GiNaC-devel] Numerical evaluation for tgamma, lgamma and beta.

Dear all, I added numerical evaluation for the functions tgamma, lgamma and beta to the CVS. The method employed is the Lanczos approximation as described on Wikepedia: http://en.wikipedia.org/wiki/Lanczos_approximation . (I also corrected some small errors on that page.) This method uses a fixed precision and tables are used to store coefficients. Currently the tables available are for maximally 20, 50, 100 and 200 digits. If Digits exceeds 200, no numerical evaluation is available. Best wishes, Chris