Opened 9 years ago
Last modified 5 years ago
#13039 new defect
improve mpmath-to-sage conversion
Reported by: | dsm | Owned by: | jason, jkantor |
---|---|---|---|
Priority: | major | Milestone: | sage-7.4 |
Component: | numerical | Keywords: | sd40.5 |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
Conversions between mpmath and sage objects don't always go smoothly when the number of digits required for the exponent is very large. This can cause problems for limiting behaviour when mpmath is used as the numerical backend for various special functions. For example:
from sage.libs.mpmath import utils as mpmath_utils sage: mpmath_utils.call(mpmath.airyai, 1e2) 2.63448215208818e-291 sage: mpmath_utils.call(mpmath.airyai, 1e4) 6.24874575695894e-289532 sage: mpmath_utils.call(mpmath.airyai, 1e8) 0.000000000000000 sage: mpmath_utils.call(mpmath.airyai, 1e16) --------------------------------------------------------------------------- OverflowError Traceback (most recent call last) /Users/mcneil/sagedev/sage-5.1.beta0/devel/sage-hack/sage/<ipython console> in <module>() /Users/mcneil/sagedev/sage-5.1.beta0/local/lib/python2.7/site-packages/sage/libs/mpmath/utils.so in sage.libs.mpmath.utils.call (sage/libs/mpmath/utils.c:5667)() /Users/mcneil/sagedev/sage-5.1.beta0/local/lib/python2.7/site-packages/sage/libs/mpmath/utils.so in sage.libs.mpmath.utils.mpmath_to_sage (sage/libs/mpmath/utils.c:4420)() /Users/mcneil/sagedev/sage-5.1.beta0/local/lib/python2.7/site-packages/sage/libs/mpmath/utils.so in sage.libs.mpmath.utils.mpfr_from_mpfval (sage/libs/mpmath/utils.c:3701)() OverflowError: Python int too large to convert to C long
This should probably return zero instead (and similarly go to an inf in the other case).
Change History (5)
comment:1 Changed 8 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:2 Changed 7 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:3 Changed 7 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:4 Changed 7 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:5 Changed 5 years ago by
- Description modified (diff)
- Milestone changed from sage-6.4 to sage-7.4
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