Opened 4 years ago

Closed 2 years ago

# wrong evaluation of infinite sum

Reported by: Owned by: burcin burcin major sage-6.3 symbolics maxima Travis Scrimshaw Jeroen Demeyer, Karl-Dieter Crisman N/A add doctest 6e7166a (Commits) 6e7166a97e56ed09a205873294aff31655e9a7fc #13973

### Description

```sage: n = var('n')
sage: sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, oo)
3/256*pi^2 - 1/32
```

The correct answer is 3/256*pi^2.

We should report this to maxima:

```(%i10) load(simplify_sum);
(%o10) /tmpbig/burcin/sage-5.4/local/share/maxima/5.26.0/share/contrib/solve_r\
ec/simplify_sum.mac
(%i11) simplify_sum(sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, inf));

2
%pi
2   ---- - 4
%pi     2
(%o11)                          ---- + --------
128      128
```

### comment:1 Changed 4 years ago by kcrisman

• Report Upstream changed from N/A to Reported upstream. No feedback yet.

I can confirm this is true in Maxima 5.28.0 as well. This is now Maxima artifact 3587514.

### comment:2 Changed 3 years ago by jdemeyer

• Reviewers set to Jeroen Demeyer
• Status changed from new to needs_review

Fixed in Maxima 5.30.0: #13973.

### comment:3 Changed 3 years ago by jdemeyer

• Report Upstream changed from Reported upstream. No feedback yet. to Fixed upstream, in a later stable release.
• Status changed from needs_review to positive_review

### comment:4 Changed 3 years ago by jdemeyer

• Milestone changed from sage-5.10 to sage-5.11

### comment:5 Changed 3 years ago by jdemeyer

• Status changed from positive_review to needs_work

### comment:6 Changed 3 years ago by jdemeyer

• Milestone changed from sage-5.11 to sage-5.12

### comment:7 Changed 2 years ago by vbraun_spam

• Milestone changed from sage-6.1 to sage-6.2

### comment:8 Changed 2 years ago by vbraun_spam

• Milestone changed from sage-6.2 to sage-6.3

### comment:9 Changed 2 years ago by pbruin

• Dependencies set to #13973
• Report Upstream changed from Fixed upstream, in a later stable release. to N/A
• Work issues set to add doctest

After #13973:

```sage: n = var('n')
sage: sum(1/((2*n-1)^2*(2*n+1)^2*(2*n+3)^2), n, 0, oo)
3/256*pi^2
```

### comment:10 Changed 2 years ago by tscrim

• Authors set to Travis Scrimshaw
• Branch set to public/ticket/inf_sum_doctest-13712
• Commit set to 6e7166a97e56ed09a205873294aff31655e9a7fc
• Status changed from needs_work to needs_review

Done (at least in someplace where I think it's natural...)

New commits:

 ​6e7166a Added doctest for ticket.

### comment:11 Changed 2 years ago by kcrisman

This is not a useful commit, unfortunately, because this depends on #13973 which isn't in 6.3.beta2, as far as I can tell. I just wasted a lot of time discovering this, and I don't have enough git prowess to figure out how to "merge" this into that ticket's tree.

### comment:12 follow-up: ↓ 13 Changed 2 years ago by tscrim

git merge trac u/pbruin/13973-maxima_update or whatever your remote for trac is (the other likely one is origin).

### comment:13 in reply to: ↑ 12 Changed 2 years ago by kcrisman

git merge trac u/pbruin/13973-maxima_update or whatever your remote for trac is (the other likely one is origin).

Apparently my remote is indeed trac but this command doesn't work, nor do I have any idea what the branch is since that ticket seems to have a branch called "a130eed".

Okay, the following sequence worked:

```\$ git fetch trac refs/heads/u/pbruin/13973-maxima_update:refs/remotes/trac/u/pbruin/13973-maxima_update
\$ git merge trac/u/pbruin/13973-maxima_update
```

This is so frustrating compared to the old system.

### comment:14 Changed 2 years ago by tscrim

Ack sorry, I meant git pull trac u/pbruin/13973-maxima_update (which, in effect, combines those two) (also in case you are unaware, you can also delete the temp branch by git branch -D name/of/branch).

### comment:15 Changed 2 years ago by kcrisman

• Reviewers changed from Jeroen Demeyer to Jeroen Demeyer, Karl-Dieter Crisman
• Status changed from needs_review to positive_review

Okay, finally I got it all working and positive review!

### comment:16 Changed 2 years ago by tscrim

Thanks. Sorry about mixing my git commands up!

### comment:17 Changed 2 years ago by vbraun

• Branch changed from public/ticket/inf_sum_doctest-13712 to 6e7166a97e56ed09a205873294aff31655e9a7fc
• Resolution set to fixed
• Status changed from positive_review to closed
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