Opened 10 years ago

Closed 8 years ago

#7357 closed enhancement (duplicate)

Add non-offset logarithmic integral, Li

Reported by: myurko Owned by: burcin
Priority: minor Milestone: sage-duplicate/invalid/wontfix
Component: calculus Keywords: beginner
Cc: myurko, benjaminfjones Merged in:
Authors: Reviewers: Karl-Dieter Crisman
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

Add the logarithmic integral, Li, with integration starting at 0 rather than 2.

Attachments (2)

li(x).patch​ (2.5 KB) - added by myurko 10 years ago.
non-offset-log-int.patch​ (2.7 KB) - added by kcrisman 10 years ago.

Download all attachments as: .zip

Change History (13)

Changed 10 years ago by myurko

comment:1 Changed 10 years ago by myurko

  • Status changed from new to needs_review

comment:2 Changed 10 years ago by kcrisman

  • Status changed from needs_review to needs_work

This is nice, but like #3401, should have some doctests indicating it works for complex input (I assume it does). The patch also depends on #3401.

Changed 10 years ago by kcrisman

comment:3 Changed 10 years ago by kcrisman

  • Authors set to Michael Yurko
  • Report Upstream set to N/A
  • Status changed from needs_work to needs_review

This patch adds these tests. It still depends on the (newest) patch at #3401, and in fact gets rid of one final thing which was only needed by the previous implementation of Li.

comment:4 Changed 10 years ago by kcrisman

  • Reviewers set to Karl-Dieter Crisman
  • Status changed from needs_review to positive_review

comment:5 Changed 10 years ago by burcin

  • Status changed from positive_review to needs_work

This needs more work. See my comments about the prec parameter at comment:10:ticket:3401.

Two different functions whose names differ only in capitalization (li and Li) is also very confusing. We need to come up with a better name for this.

comment:6 Changed 9 years ago by burcin

  • Keywords beginner added

comment:7 Changed 8 years ago by kcrisman

  • Cc benjaminfjones added

This seems to be addressed in the context of a much bigger overhaul by #11143. But there the name is... more complicated.

comment:8 Changed 8 years ago by benjaminfjones

Yes, this would duplicate work done in #11143. The function added there is a fully symbolic function with numerical evaluation handled by mpmath. I think that is superior to the one defined here which is just a wrapper for the mpmath call.

The function added in #11143 is really a class called Function_exp_integral_li and it has an alias exp_integral_li to match the other exponential integrals. #11143 also moves all the exponential integrals to a new module under sage/functions so this would conflict with that design decision too.

comment:9 Changed 8 years ago by kcrisman

  • Milestone changed from sage-4.7.2 to sage-duplicate/invalid/wontfix

So this can be closed as duplicate, correct? Except I really would love it to be called Li instead of something horribly long... either way, feel free to review this as positive; I'm changing the milestone.

comment:10 Changed 8 years ago by kcrisman

  • Authors Michael Yurko deleted
  • Status changed from needs_work to positive_review

This is definitely and definitively duplicated by the much more comprehensive #11143.

comment:11 Changed 8 years ago by jdemeyer

  • Resolution set to duplicate
  • Status changed from positive_review to closed
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