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From: "Helen " <helenlegakis@hotmail.com>
Newsgroups: comp.soft-sys.matlab
Subject: gamma function with 2 parameters
Date: Fri, 7 Dec 2007 01:41:43 +0000 (UTC)
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Hi everyone.

I am trying to find the summation of the following symbolic
expression 

(z^k)/(n+k)!

with respect to its symbolic variable k from 0 to 2m-1.

I have done this as follows

>> syms n real
>> syms k real
>> syms z real
>> syms m real
>> simplify(symsum((z^k)/maple('factorial', n+k), k, 0, 2*m-1))

(For some reason symsum((z^k)/factorial(n+k), k, 0, 2*m-1)
does not work.)


and I obtain

ans =
 
z^(-n)*exp(z)*(-gamma(n,z)*gamma(2*m+n)+gamma(2*m+n,z)*gamma(n))/gamma(n)/gamma(2*m+n)

Why does gamma have 2 parameters? The gamma function can
only have one input argument

Please help.
Helen