[SciPy-Dev] adding chkfinite flags to linalg functions

[Stéfan van der Walt]

On Sat, Sep 17, 2011 at 5:11 AM, Martin Teichmann
<lkb.teichmann at gmail.com> wrote:
> * adding a ALLFINITE flag to ndarrays. Gaël correctly pointed out that
> this is not as simple as it sounds, but it's nevertheless possible:
> ALLFINITE would have to be a immutable flag at creation time of the
> ndarray, and everytime one does something to the ndarray (possibly
> via a view, to which the ALLFINITE flag has to be copied), we have
> to check everything is finite. This solution would create a lot of work,
> but also nice side-effects: even NaN-aware functions in numpy can
> be very slow on some (actually very common) hardware, accidental
> NaNs can be very annoying.

I don't think this is possible.  Think, for example, of a ctypes call
that simply receives the array data pointer, and then directly
operates on memory.  There is no way for the array to know that this
is happening.

Regards
Stéfan