Opened 8 years ago
Last modified 3 years ago
#16586 new defect
K.zeta_function() unstable
Reported by: | rws | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.4 |
Component: | number fields | Keywords: | zeta, dokchitser, precision, lseries |
Cc: | jakobkroeker | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
This was reported by parzan in http://ask.sagemath.org/question/8418/zeta-function-gone-wild/
sage: K.<a> = NumberField(x^2-2) sage: K.zeta_function()(7) 82.7603619399160 sage: K.zeta_function(prec=100)(7) 45333.379954778857657650185188 sage: K.zeta_function(prec=200)(7) 5.6555192254423051174292272646037247772094677139829119697339e8
See that excellent bug report for more aspects of the matter. Setting Component:
to scripts because it seems to be a Dokchitser issue. See also #4940.
Change History (5)
comment:1 Changed 8 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:2 Changed 8 years ago by
- Component changed from scripts to number fields
comment:3 Changed 5 years ago by
- Cc jakobkroeker added
comment:4 Changed 3 years ago by
comment:5 Changed 3 years ago by
This works now with the default algorithm. Still fails with Dokchitser's scripts:
sage: K.zeta_function(prec=100, algorithm="pari")(7) 1.0078766798859009530335817870 sage: K.zeta_function(prec=100, algorithm="gp")(7) 45333.379954778857657650185188
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This strange behaviour happens at odd integers >=7 only:
and the value depends strongly on the cutoff parameter
This suggests something fishy in the dokchitser scripts..