[SciPy-Dev] scipy.special.expi complex test failure with scipy 0.9, numpy 1.6.1dev

[Charles R Harris]

On Fri, May 20, 2011 at 6:33 PM, Pauli Virtanen <pav at iki.fi> wrote:

> On Fri, 20 May 2011 17:43:54 -0600, Charles R Harris wrote:
> [clip: expi]
> > Curious. I don't see this on ubuntu, it looks like a factor of 2*pi*1j
> > is getting added on. Looks like a corner case involving complex log or
> > some such.
>
> The implementation is based on calculating E1(-z), and cancelling out
> the i*pis with a logarithm. It's a bit of a bad form on the real axis,
> and apparently the branch cuts are not consistently chosen with MKL.
> I'd guess the values will be OK away from the real axis, though,
> but some rewriting probably needs to be done.
>
>
IIRC, the default flags for compiling with MKL on Windows changed between
1.5 and 1.6. I wonder if that has anything to do with this?

Chuck
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