serious bug in sum

[William Stein]

Hi Sage-Devel,

I wanted to raise the profile of #10682, since it's a bug in which
Sage's sum command (which calls maxima) outputs a very wrong answer.

http://trac.sagemath.org/sage_trac/ticket/10682

William

--
William Stein
Professor of Mathematics
University of Washington
http://wstein.org

[rjf]

maxima 5.25.1, at least for me, gets the right answer
....

load(simplify_sum);
simplify_sum(sum (binomial(n,k)*k^2, k, 2, n));

returns


((n^2+n)*2^n-4*n)/4


This raises an interesting point. If Sage were to get
GSOC approval to be a mentoring organization, would it
match mentors and students to fix bugs in Maxima?

RJF

[William Stein]

On Sunday, February 26, 2012, rjf <fat...@gmail.com> wrote:
> maxima 5.25.1, at least for me, gets the right answer
> ....
>
> load(simplify_sum);
> simplify_sum(sum (binomial(n,k)*k^2, k, 2, n));
>
> returns
>
>
> ((n^2+n)*2^n-4*n)/4
>

That's good - thanks for checking...

>
> This raises an interesting point.  If Sage were to get
> GSOC approval to be a mentoring organization, would it
> match mentors and students to fix bugs in Maxima?
>

If there were a solid proposal then *definitely* yes!   And the same goes for any other component of Sage.

 - william

> RJF
>
>
>
> On Feb 26, 11:56 am, William Stein <wst...@gmail.com> wrote:
>> Hi Sage-Devel,
>>
>> I wanted to raise the profile of #10682, since it's a bug in which
>> Sage's sum command (which calls maxima) outputs a very wrong answer.
>>
>> http://trac.sagemath.org/sage_trac/ticket/10682
>>
>> William
>>
>> --
>> William Stein
>> Professor of Mathematics
>> University of Washingtonhttp://wstein.org
>

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[kcrisman]

On Feb 26, 8:33 pm, William Stein <wst...@gmail.com> wrote:

> On Sunday, February 26, 2012, rjf <fate...@gmail.com> wrote:
> > maxima 5.25.1, at least for me, gets the right answer
> > ....
>
> > load(simplify_sum);
> > simplify_sum(sum (binomial(n,k)*k^2, k, 2, n));
>
> > returns
>
> > ((n^2+n)*2^n-4*n)/4
>
> That's good - thanks for checking...
>
>
>
> > This raises an interesting point.  If Sage were to get
> > GSOC approval to be a mentoring organization, would it
> > match mentors and students to fix bugs in Maxima?
>
> If there were a solid proposal then *definitely* yes!   And the same goes
> for any other component of Sage.
>

That would be great, yes!

[Harald Schilly]

On Monday, February 27, 2012 2:25:58 AM UTC+1, rjf wrote:

If Sage were to get
GSOC approval to be a mentoring organization, would it
match mentors and students to fix bugs in Maxima?

An hour ago I started a thread for project proposals. In this case I would suggest that this needs two mentors  (or one who is good at both). One that is familiar with Sage and another one with Maxima. Just email me for more details or write me a project description.

H

[Dima Pasechnik]

This is all fixed by update of maxima to 5.26, and the corresponding patch.

The ticket is ready for review!