[R] sum to infinity

[David Winsemius]

On Sep 13, 2010, at 5:24 AM, tuggi wrote:

>
> hello,
>
> can i calculate a sum to infinity in R.
> i want to do something like this:
>
> \sum_{i=0}^\infty
> \frac{2^{-d-1}}{\Gamma(\frac{d-1}{2})}\left(\frac{\Gamma(2d-3)(2- 
> d)_{i}\Gamma(i+1,-z/2)2^{i+1}}{\Gamma(d-1)(4-2d)_{i}i!}\right)+
> \\
> \sum_{i=0}^\infty
> \frac{2^{-d-1}}{\Gamma(\frac{d-1}{2})}\left(\frac{\Gamma(3-2d) 
> (d-1)_{i}\Gamma(2d-2+i,-z/2)2^{2d-2+i}}{\Gamma(2-d)(2d-2)_{i}}\right),
>
> where (a)_{i}=\Gamma(a+i) / \Gamma(a) .
> I hope someone can help me.

Are you aware of the RYacas interface to the symbolic algebra YACAS.  
(I'm not sure I have all the caps set correctly, but your search  
engine probably won't care.)


-- 
David Winsemius, MD
West Hartford, CT