arccosh for complex numbers, goofy choice of branch
17 Mar
2008
17 Mar
'08
4:40 a.m.
OK, Which branch do we want to use. As it currently is in numpy and scipy.special arccosh(1.5) = 0.96242365011920694 arccosh(1.5+0j) = -0.96242365011920705 + 0.0j This is consistent with gsl, but inconsistent with Mathematica, NAG, Maple, and probably all sensible implementations which use the generally accepted principal value. I've left this inconsistency raising an error in the ufunc tests until we make a decision. It might be nice to know what FORTRAN and MatLab do with this. Chuck
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participants (7)
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Charles R Harris
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Gary Strangman
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lorenzo bolla
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Nils Wagner
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Pauli Virtanen
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Robert Kern
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Travis E. Oliphant