[Numpy-discussion] Numpy.linalg.eig oddity

[David Goldsmith]

Is it not possible to update your versions to see if that solves the
problem?

DG

On Wed, Jun 23, 2010 at 11:25 AM, Salim, Fadhley (CA-CIB) <
fadhley.salim at ca-cib.com> wrote:

> I've been investigating a truly bizarre bug related to the use of
> numpy.linalg.eig.
>
> I have two classes which both use numpy.linalg.eig. These classes are
> used at very different times and are not connected in any way other than
> the fact that they both share this particular dependancy.
>
> I have found that whichever class is called second will produce a
> slightly different answer if numpy.linalg.eig is used sometime earlier.
> I've eliminated all other variables besides the call to eig(). This
> seems completely implausible, and yet I have the data.
>
> As far as I am aware, eig() is wholly stateless and therefore using it
> should not affect any subsequent calls to the function, right?
>
> Numpy==1.2.1, Scipy==0.7.0
>
> I've checked the bug-trac for this function and can find no references
> to bugs which cause it to hold-state, even in the somewhat out of date
> version of numpy. Can somebody let me know if there's something that I'm
> missing.
>
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-- 
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set is non-empty, even if that set has measure zero.

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