Opened 12 years ago
Last modified 6 weeks ago
#11505 new defect
ideals_of_bdd_norm misterious bug?
Reported by: | mmasdeu | Owned by: | davidloeffler |
---|---|---|---|
Priority: | minor | Milestone: | |
Component: | number fields | Keywords: | ideallist, ideals of bounded norm, memory |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Here is a code that I try to run in my laptop:
sage: R.<t>=QQ['x'] sage: F.<a>=NumberField(t^2-t-7) sage: V=F.ideals_of_bdd_norm(150000) sage: assert(len(V[14369])>0) sage: I=F.ideal(V[14369][0]) sage: assert(I.norm()==14369)
The last assertion should not complain, because ideals_of_bdd_norm(N) should return a dict of integral ideals of norm up to N, indexed by the norm.
I have only observed this when I ask for very large norms (I would like to go up to 10e6, and the above is the smallest example that I got). If I ask for norms up to 15000 say, then it works as expected.
I suspect that it is a problem with the communication with pari, but I don't know enough about it to tell. Also, I should say that this doesn't happen in other (bigger) machines that I have tried, so it might be architecture-related, or maybe memory dirtyness...
I am running this on Sage 4.7, on a Thinkpad X41t with an updated Arch distribution, if that is of any help. Also I will be happy to do more tests if asked, of course!
Change History (6)
comment:1 Changed 10 years ago by
comment:2 Changed 9 years ago by
Milestone: | sage-5.11 → sage-5.12 |
---|
comment:3 Changed 9 years ago by
Milestone: | sage-6.1 → sage-6.2 |
---|
comment:4 Changed 9 years ago by
Milestone: | sage-6.2 → sage-6.3 |
---|
comment:5 Changed 9 years ago by
Milestone: | sage-6.3 → sage-6.4 |
---|
comment:6 Changed 6 weeks ago by
Milestone: | sage-6.4 |
---|
I just ran the code and the first assert failed, i.e.
len(V[14369])
is 0 for me. And it should be since 14369 is inert in that quadratic field and so is not the norm of an ideal of that field.