Opened 3 years ago
Closed 3 years ago
#27574 closed enhancement (fixed)
py3: fix one doctest in French book
| Reported by: | chapoton | Owned by: | |
|---|---|---|---|
| Priority: | major | Milestone: | sage-8.8 |
| Component: | python3 | Keywords: | |
| Cc: | tscrim, vklein | Merged in: | |
| Authors: | Frédéric Chapoton | Reviewers: | Travis Scrimshaw |
| Report Upstream: | N/A | Work issues: | |
| Branch: | f81acd9 (Commits, GitHub, GitLab) | Commit: | f81acd951b977a257be0df276b15c47c18ae4942 |
| Dependencies: | Stopgaps: |
Status badges
Description
by marking it as random
Change History (9)
comment:1 Changed 3 years ago by
- Branch set to u/chapoton/27574
- Commit set to f81acd951b977a257be0df276b15c47c18ae4942
- Status changed from new to needs_review
comment:4 Changed 3 years ago by
I don't really like marking tests as random when there is exact output. I think the better thing to do is to change the test to check that the output matches something explicit.
comment:5 Changed 3 years ago by
Well, I have not read the book, but this precise doctest is probably here to display an example of bad answer, by lack of sufficient precision...
comment:6 Changed 3 years ago by
page 201 of the book (http://sagebook.gforge.inria.fr/english.html)
Let us continue. For the following system, J.variety() computes (exactly) a
triangular decomposition of J, then finds numerically the real solutions of the
obtained system(s). This yields a unique real solution:
sage: R.<x,y> = QQ[]; J = ideal([ x^7-(100*x-1)^2, y-x^7+1 ])
sage: J.variety(RealField(51))
[{y: 396340.890166545, x: -14.1660266425312}]
Yet, by performing the computation exactly until the end, we see there are three
real solutions, and the value of x in the above numerical solution is completely
wrong:
comment:7 Changed 3 years ago by
Based on that, I am more convinced that we should make sure it is testing the correct output and not just something from a valid computation. However, there is something very annoying happening when I try to test against the value exactly. The x value does not quite match despite having the same digits displayed. So I guess we just have to let this be with # random. :/
comment:8 Changed 3 years ago by
- Reviewers set to Travis Scrimshaw
- Status changed from needs_review to positive_review
comment:9 Changed 3 years ago by
- Branch changed from u/chapoton/27574 to f81acd951b977a257be0df276b15c47c18ae4942
- Resolution set to fixed
- Status changed from positive_review to closed
New commits:
py3: mark one doctest as random in the French book