Opened 13 years ago
Closed 13 years ago
#6961 closed enhancement (fixed)
provide wrapper for psi function of GiNaC
Reported by: | Burcin Erocal | Owned by: | |
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Priority: | major | Milestone: | sage-4.3.3 |
Component: | symbolics | Keywords: | psi, gamma, digamma, polygamma |
Cc: | Merged in: | sage-4.3.3.alpha1 | |
Authors: | Burcin Erocal | Reviewers: | Karl-Dieter Crisman, Ross Kyprianou, Minh Van Nguyen |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
From sage-support:
On Fri, 18 Sep 2009 15:47:45 -0700 (PDT) The_Fool <masterfulet@yahoo.com> wrote: > While working with the derivative of the Gamma function, the digamma > function is obviously involved. The sage "diff" function does show Γ > '(x) == Γ(x)ψ(x) like it should, however, the digamma function (called > psi in sage) is not defined whenever I try to do anything with it. It > seems as if only the output of "diff" can use this function.
psi()
is defined in GiNaC, but we don't provide wrappers for it.
Defining a function psi
, similar to the way arctan2
is defined in line 422 of sage/functions/trig.py
should fix this.
The sage-support thread is here:
http://groups.google.com/group/sage-support/browse_thread/thread/1ad313c921b7dbc0
Attachments (3)
Change History (15)
comment:1 Changed 13 years ago by
comment:2 Changed 13 years ago by
Authors: | → Burcin Erocal |
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Report Upstream: | → N/A |
Status: | new → needs_work |
It turns out defining this function wasn't as straightforward as I thought. Pynac defines 2 functions with the same name psi
. :)
attachment:trac_6961-psi.patch wraps these 2 functions, and provides a global psi()
to call the appropriate one. Unpickling these correctly requires changes in pynac. I'll make a new pynac package available later this week.
comment:3 follow-up: 7 Changed 13 years ago by
Status: | needs_work → needs_review |
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comment:4 Changed 13 years ago by
Status: | needs_review → needs_work |
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Work issues: | → needs rebase on top of #6207 |
The patch on this ticket conflicts with #6207. If I first apply the patches on #6207 to Sage 4.3.1, and then trac_6961-psi.patch, I would get a hunk failure:
[mvngu@sage sage-main]$ hg qimport http://trac.sagemath.org/sage_trac/raw-attachment/ticket/6207/trac_6207.patch && hg qpush adding trac_6207.patch to series file applying trac_6207.patch now at: trac_6207.patch [mvngu@sage sage-main]$ hg qimport http://trac.sagemath.org/sage_trac/raw-attachment/ticket/6207/trac_6207-part2.patch && hg qpush adding trac_6207-part2.patch to series file applying trac_6207-part2.patch now at: trac_6207-part2.patch [mvngu@sage sage-main]$ hg qimport http://trac.sagemath.org/sage_trac/raw-attachment/ticket/6207/trac_6207-review.patch && hg qpush adding trac_6207-review.patch to series file applying trac_6207-review.patch now at: trac_6207-review.patch [mvngu@sage sage-main]$ hg qimport http://trac.sagemath.org/sage_trac/raw-attachment/ticket/6961/trac_6961-psi.patch && hg qpush adding trac_6961-psi.patch to series file applying trac_6961-psi.patch patching file sage/symbolic/pynac.pyx Hunk #2 FAILED at 1566 1 out of 3 hunks FAILED -- saving rejects to file sage/symbolic/pynac.pyx.rej patch failed, unable to continue (try -v) patch failed, rejects left in working dir errors during apply, please fix and refresh trac_6961-psi.patch
Perhaps you want to rebase trac_6961-psi.patch on top of #6207?
comment:5 Changed 13 years ago by
Status: | needs_work → needs_review |
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comment:6 Changed 13 years ago by
The unrebased patch is fine; I can't get the other patches in the symbolics queue to work off of the rebase, not yet anyway.
If there is time, would it be possible to make an alias polygamma = psi2? Not just because Mma uses it, but because a lot of references call it that (such as the ones a students of mine is using for some research) in written form. This is great functionality to add, though.
comment:7 Changed 13 years ago by
Replying to burcin:
New pynac package available here:
http://sage.math.washington.edu/home/burcin/pynac/pynac-0.1.11.spkg
Now apparently at boxen.math instead.
comment:8 Changed 13 years ago by
Keywords: | psi gamma digamma polygamma added |
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Reviewers: | → Karl-Dieter Crisman, Ross Kyprianou |
Status: | needs_review → positive_review |
sage: diff(gamma(x),x)/gamma(x) # definition of digamma (or "psi") psi(x) sage: diff(gamma(x),x).subs(x=1) -euler_gamma sage: psi(1) -euler_gamma # analytical result sage: psi(1/2) -euler_gamma - 2*log(2) # numerical examples sage: psi(.5) -1.96351002602142 sage: psi(.5r) -1.9635100260214233 sage: psi(complex(.5)) (-1.9635100260214233+0j) # 1st argument means 0'th derivative (so psi(0, x) = psi(x)) sage: psi(0, .5) psi(0.500000000000000) sage: N(psi(0, .5)) -1.96351002602142
comment:9 Changed 13 years ago by
Status: | positive_review → needs_work |
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Work issues: | needs rebase on top of #6207 |
comment:10 Changed 13 years ago by
Reviewers: | Karl-Dieter Crisman, Ross Kyprianou → Karl-Dieter Crisman, Ross Kyprianou, Minh Van Nguyen |
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Status: | needs_work → needs_review |
I applied patches in the following order against Sage 4.3.3.alpha0, together with the updated package pynac-0.1.11.spkg:
- #6961: trac_6961-psi.rebased.patch
- #7822: trac_7822-py_log.take2.patch
- #7876: trac_7876-pynac_print.take2.patch
- #7363
- #7957
- #7916: trac_7916-same_name_method.take2.patch
- #6465:
- #6559:
All doctests passed except for this trivial failure:
[mvngu@sage sage-4.3.3.alpha0.1]$ ./sage -t -long devel/sage/sage/rings/arith.py sage -t -long "devel/sage/sage/rings/arith.py" ********************************************************************** File "/dev/shm/mvngu/sandbox/sage-4.3.3.alpha0.1/devel/sage/sage/rings/arith.py", line 287: sage: factorial(-32) Expected: Traceback (most recent call last): ... ValueError: factorial -- self = (-32) must be nonnegative Got: Traceback (most recent call last): File "/dev/shm/mvngu/sandbox/sage-4.3.3.alpha0.1/local/bin/ncadoctest.py", line 1231, in run_one_test self.run_one_example(test, example, filename, compileflags) File "/dev/shm/mvngu/sandbox/sage-4.3.3.alpha0.1/local/bin/sagedoctest.py", line 38, in run_one_example OrigDocTestRunner.run_one_example(self, test, example, filename, compileflags) File "/dev/shm/mvngu/sandbox/sage-4.3.3.alpha0.1/local/bin/ncadoctest.py", line 1172, in run_one_example compileflags, 1) in test.globs File "<doctest __main__.example_3[10]>", line 1, in <module> factorial(-Integer(32))###line 287: sage: factorial(-32) File "/dev/shm/mvngu/sandbox/sage-4.3.3.alpha0.1/local/lib/python/site-packages/sage/rings/arith.py", line 315, in factorial raise ValueError, "factorial -- must be nonnegative" ValueError: factorial -- must be nonnegative ********************************************************************** 1 items had failures: 1 of 11 in __main__.example_3 ***Test Failed*** 1 failures. For whitespace errors, see the file /dev/shm/mvngu/dot_sage/tmp/.doctest_arith.py [50.3 s]
The failure is fixed via trac_6961-doctest.patch, so only this latter patch needs some reviewing love. I'm happy with both #6465 and #6559. If my patch is OK, then these 8 tickets can be closed: #6961, #7822, #7876, #7363, #7957, #7916, #6465, #6559.
comment:11 Changed 13 years ago by
Status: | needs_review → positive_review |
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Hi Minh,
Your patch looks ok to me. I'm switching this to positive review.
It's be truly awesome if all those tickets can get merged in this release. :)
Cheers,
Burcin
comment:12 Changed 13 years ago by
Merged in: | → sage-4.3.3.alpha1 |
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Resolution: | → fixed |
Status: | positive_review → closed |
More precisely:
but "psi" is unknown to Sage...