Opened 9 years ago

Last modified 8 years ago

## #14620 new enhancement

# adaptive numerical approximation

Reported by: | Vincent Delecroix | Owned by: | Vincent Delecroix |
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Priority: | major | Milestone: | sage-6.4 |

Component: | numerical | Keywords: | numerical_approx |

Cc: | Merged in: | ||

Authors: | Reviewers: | ||

Report Upstream: | N/A | Work issues: | |

Branch: | Commit: | ||

Dependencies: | Stopgaps: |

### Description

It would be nice to have an adaptive algorithm for numerical evaluation of expression and number field elements. This would avoid the following behavior

sage: a = (106*pi - 333) / (355 - 113*pi) sage: a.n(digits=5) Traceback (most recent call last) ... ValueError: power::eval(): division by zero sage: a.n(digits=6) 289.000 sage: a.n(digits=7) 289.0000 sage: a.n(digits=8) 293.65079 sage: a.n(digits=9) 292.772502 sage: a.n(digits=10) 292.6277805 sage: a.n(digits=11) 292.63234726

where we can not rely on the last digits.

See the discussion on this sage-devel thread

### Change History (4)

### comment:1 Changed 9 years ago by

Milestone: | sage-5.11 → sage-5.12 |
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### comment:2 Changed 9 years ago by

Milestone: | sage-6.1 → sage-6.2 |
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### comment:3 Changed 8 years ago by

Milestone: | sage-6.2 → sage-6.3 |
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### comment:4 Changed 8 years ago by

Milestone: | sage-6.3 → sage-6.4 |
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