[SciPy-dev] Dealing with precision problem: warning vs raise

[Robert Kern]

On Wed, Nov 5, 2008 at 20:05, David Cournapeau <cournape at gmail.com> wrote:
> Hi,
>
> I was looking at bug #651, related to finding the roots of a
> polynomial with too small coefficients. Currently, the small values
> are discarded by the function in #651, which I find a bid surprising
> (it may not be obvious to the user why it gets no zero for a
> polynomial of order N). Wouldn't it be better to raise an exception or
> a at least a warning instead (I was thinking about doing that in
> numpy.roots instead, but that may be too drastic, as it would break
> some code - maybe it is desirable, though, as the values in that case
> are more or less meaningless )

Issue a warning using warnings.warn(). Users may use the warnings
module to turn it into an exception should they so desire.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco