improved hypsum non-convergence behaviour #651
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skirpichev
requested changes
May 12, 2023
| return ctx.hypsum(2, 1, (atype, btype, ctype), [a, b, c], z, **kwargs) | ||
| except ctx.NoConvergence: | ||
| if kwargs.get('force_series', False): | ||
| raise |
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Please add a test for this case, see https://app.codecov.io/gh/mpmath/mpmath/pull/651
|
Ok, I've cherry-picked this commit in #703. |
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This change includes two
hypsumrelated fixes:ValueErrorexception, raised inmp.hypsumwhen encountering convergence problems, into a more appropriateNoConvergenceexception - just asfp.hypsumdoes already.NoConvergenceexception withing the "fast path" ofhyp2f1. The same behavior is already used in the "fast path"s of_hyp2f0,_hypq1fq, and_hyp_borel- and was broken sincehypsumnever raised the expectedNoConvergenceexception (in thempcontext). Similar to_hyp2f0, this behavior can be suppressed with the keyword argumentforce_series=True.I've also seen that similar issues may be affecting
hypercomb, since it also raiseValueErrorinstead ofNoConvergenceto signal convergence issues. If interested, I could also change that function appropriately.I've verified in known pathological case (
mpmath.hyp2f1(3814.269794854973, -1985.4387491751415, 5369.1679108495828, 0.70000000000000007).ae('4.1656634124024037e-532')) that both "fast path" (with raisedmaxprec) and the "slow path" (which is actually faster) bow yield the same result. If interested, I can also add this as a test case.This change may positivity affect some of the cases alluded to in #296. For the issues #14 and #495 it shifts the convergence issue into the "slow path", which may be preferable.