This is not a bug.
GosperSum works in very special cases.
In particular the range should not contain
a parameter.
A more general package is "simplify_sum".
Use
load(zeilberger);
simplify_sum(sum(<formula>,k,1,N));
Fabrizio
On Wed, 1 Oct 2008, Alexei Meremianin wrote:
> Maybe this will help.
> the simplest situation when the bug pops up:
> (%i5) GosperSum ( (N-k+1), k, 1, N);
> Division by 0
> # 0: GosperSumVerboseOpt(f=N-k+1,k=k,a=1,b=N,mode=0)(Gosper.mac line 247)
> # 1: GosperSum(f=N-k+1,k=k,a=1,b=N)(Gosper.mac line 253)
> -- an error. To debug this try debugmode(true);
>
> ciao,
> Alexei Meremianin
>
>
> Fabrizio Caruso wrote:
>> Thanks for your bug report
>>
>> I promise I'll look into it and try to fix the problem.
>>
>> Fabrizio
>>
>>
>>
>> On Wed, 24 Sep 2008, Alexei Meremianin wrote:
>>
>> > Hello,
>> >
>> > I have encountered the problem with the GosperSum.
>> > This is it
>> > -----------------------------
>> > Maxima 5.16.3 http://maxima.sourceforge.net
>> > Using Lisp CLISP 2.41 (2006-10-13)
>> > Distributed under the GNU Public License. See the file COPYING.
>> > Dedicated to the memory of William Schelter.
>> > The function bug_report() provides bug reporting information.
>> > (%i1) load(zeilberger);
>> > (%o1) /usr/share/maxima/5.16.3/share/contrib/Zeilberger/zeilberger.mac
>> > (%i2) GosperSum( (N-mu+1)*(N-M-mu+1), mu, 1, N);
>> > Division by 0
>> > #0:
>> > GosperSumVerboseOpt(f=(N-mu+1)*(N-M-mu+1),k=mu,a=1,b=N,mode=0)(Gosper.mac
>> > line 247)
>> > #1: GosperSum(f=(N-mu+1)*(N-M-mu+1),k=mu,a=1,b=N)(Gosper.mac line 253)
>> > -- an error. To debug this try debugmode(true);
>> > (%i3)
>> >
>> > -----------------------------
>> > Hope it will help you to improve the nice maxima packet.
>> >
>> > cheers,
>> > Alexei Meremianin
>> >
>> > PS. Are there plans to handle infinite summations?
>> > I mean to convert them to hypergeometric functions.
>> >
>