Resource for fast algorithm computation of special functions

[BigMoosie]

It seems hard to find algorithms on the web for computing functions like erf() and zeta() etc. Many sites offer algorithmic solutions at a cost, but my project is non profit so I don't want to spend money on it (it will be released free of charge as a web application).

 

So I am wondering if anybody knows a good algorithm for computing these functions for general complex numbers expressed as (a+bi). The ideal algorithm will be one that is iterative or recursive allowing an arbitrary level of accuracy, and solutions that converge quickly.

 

Right now I need 'erf', 'zeta' and 'gamma' (I have one for gamma but it only calculates real arguments).

 

Other popular special functions that cannot be expressed in terms of these three would also be a bouns.

 

Cheers,

- Moosie

[Bignose]

netlib.org is one that I use a lot. Have you looked around there?

[BigMoosie]

Bignose, thanks, the site looks good, but the functions I am after seem to only have algorithms for real z there (no Complex algorithms.