cosine_series_coefficient hangs

[wdjoyner]

This is a method of the Piecewise class (which I use almost on a daily basis in teaching):

sage: f1 = lambda x: x*(pi-x)
sage: f = Piecewise([[(0,pi),f1]])
sage: f.cosine_series_coefficient(0,pi)
                                               

Requires a ctl-c.

Component: calculus

Issue created by migration from https://trac.sagemath.org/ticket/4616

[sagetrac-mabshoff]

comment:1

I can confirm this problem on a box that has no problem with the Sage <-> Maxima communication (I was dubious initially since David has reported problems with Maxima for his recent Sage installs).

Cheers,

Michael

[wdjoyner]

comment:2

Does #4693 fix this bug?

[sagetrac-mabshoff]

comment:3

Yes, #4693 fixes the bug:

mabshoff@sage:/scratch/mabshoff/release-cycle/sage-3.2.2.alpha0$ ./sage
----------------------------------------------------------------------
| Sage Version 3.2.1, Release Date: 2008-12-01                       |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
sage: f1 = lambda x: x*(pi-x)
sage: f = Piecewise([[(0,pi),f1]])
sage: f.cosine_series_coefficient(0,pi)
pi^2/3
sage: 
Exiting SAGE (CPU time 0m0.17s, Wall time 2m3.53s).
Exiting spawned Maxima process.

Do you want to add a doctest so we can close this?

Cheers,

Michael

[wdjoyner]

comment:4

I would but I still can't apply the patch for #4693:

----------------------------------------------------------------------
| Sage Version 3.2.1, Release Date: 2008-12-01                       |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
Loading Sage library. Current Mercurial branch is: piecewise2
sage: hg_sage.apply("/Volumes/G-DRIVE-MINI/sagestuff/trac_4693.2.patch")
cd "/Volumes/G-DRIVE-MINI/sagestuff/sage-3.2.rc1/devel/sage" && hg status
cd "/Volumes/G-DRIVE-MINI/sagestuff/sage-3.2.rc1/devel/sage" && hg status
cd "/Volumes/G-DRIVE-MINI/sagestuff/sage-3.2.rc1/devel/sage" && hg import   "/Volumes/G-DRIVE-MINI/sagestuff/trac_4693.2.patch"
applying /Volumes/G-DRIVE-MINI/sagestuff/trac_4693.2.patch
patching file sage/functions/piecewise.py
Hunk #25 FAILED at 717
1 out of 44 hunks FAILED -- saving rejects to file sage/functions/piecewise.py.rej
abort: patch failed to apply
sage: 

[rlmill]

comment:5

Attachment: trac-4616.patch.gz

Verified that this is now fixed, attached a patch with a doctest.

[wdjoyner]

comment:6

I can read the docstring and check in Sage that it is correct. (I did not try to apply it though.)

----------------------------------------------------------------------
| Sage Version 3.2.3, Release Date: 2009-01-05                       |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
sage: f1 = lambda x: x*(pi-x)
sage: f = Piecewise([[(0,pi),f1]])
sage: f.cosine_series_coefficient(0,pi)
pi^2/3

Hope this is sufficient for a positive review.

[sagetrac-mabshoff]

comment:7

Merged in Sage 3.3.alpha1

Cheers,

Michael