#10484 closed defect (fixed)
Chinese remainder code raises an error when called with Python ints
Reported by: | davidloeffler | Owned by: | was |
---|---|---|---|
Priority: | major | Milestone: | sage-4.6.2 |
Component: | number theory | Keywords: | CRT |
Cc: | Merged in: | sage-4.6.2.alpha0 | |
Authors: | David Loeffler | Reviewers: | Robert Bradshaw, Mike Hansen |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Lots of the congruence subgroup code works intensively with small integers, and represents these as Python ints rather than Sage integers for speed reasons. This brought to light the following irritating bug:
sage: crt(int(2), int(3), int(5), int(7)) --------------------------------------------------------------------------- AttributeError Traceback (most recent call last) /storage/masiao/sage-4.6.1.alpha3/devel/sage-reviewing/<ipython console> in <module>() /usr/local/sage/sage-4.6/local/lib/python2.6/site-packages/sage/rings/arith.pyc in crt(a, b, m, n) 2737 return CRT_list(a, b) 2738 g, alpha, beta = XGCD(m, n) -> 2739 q, r = (b - a).quo_rem(g) 2740 if r != 0: 2741 raise ValueError("No solution to crt problem since gcd(%s,%s) does not divide %s-%s" % (m, n, a, b)) AttributeError: 'int' object has no attribute 'quo_rem'
Attachments (1)
Change History (8)
comment:1 Changed 11 years ago by
- Status changed from new to needs_review
comment:2 Changed 11 years ago by
- Status changed from needs_review to positive_review
comment:3 Changed 11 years ago by
- Reviewers set to Robert Bradshaw, Mike Hansen
- Status changed from positive_review to needs_info
Shouldn't you use Integer(a)
instead of ZZ(a)
since it's about 3.5 times faster (on boxen)?
comment:4 Changed 11 years ago by
- Status changed from needs_info to needs_review
Here's a new patch using Integer. Sorry, I meant to overwrite the original patch -- apply only the second one.
comment:6 Changed 11 years ago by
- Merged in set to sage-4.6.2.alpha0
- Resolution set to fixed
- Status changed from positive_review to closed
comment:7 Changed 11 years ago by
- Reviewers changed from Robert Bradshaw, Mike Hansen to Robert Bradshaw, Mike Hansen
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Here's a tiny little patch (one line, one comment, one doctest).