[Numpy-discussion] Numarray - Numeric incompatibility

[Todd Miller]

On Thu, 2003-09-18 at 13:53, Tim Hochberg wrote:
> 
> I'm just starting to move some of my code over to numarray and I was 
> dismayed to find that basic operation between Numeric and numarray 
> arrays fail.
> 
>  >>> import Numeric as np
>  >>> import numarray as na
>  >>> a = na.arange(5)
>  >>> p = np.arange(5)
>  >>> a + p
> ['vector', 'vector']
> Traceback (most recent call last):
>   File "<stdin>", line 1, in ?
>   File "C:\Python23\Lib\site-packages\numarray\numarraycore.py", line 
> 648, in __add__
>     def __add__(self, operand): return ufunc.add(self, operand)
>   File "C:\Python23\lib\site-packages\numarray\ufunc.py", line 818, in 
> _cache_miss2
>     key = (_digest(n1), _digest(n2), _digest(out), safethread.get_ident())
> KeyError: '_digest force cache miss'
> 
> I suspect (hope!) that this is just a bug and not something inherent in 
> numarray. 

It's an interoperability issue.  Please let us know if you find others.

> I dug around in unfunc.py a bit and it appears that the bug is 
> shallow and can be fixed simply by replacing::
> 
>          if not (_sequence(n1) or _sequence(n2)):
>             key = (_digest(n1), _digest(n2), _digest(out), 
> safethread.get_ident())
>             self._cache[ key ] = cached
> 
> with::
> 
>         try:
>             key = (_digest(n1), _digest(n2), _digest(out), 
> safethread.get_ident())
>         except KeyError:
>             pass
>         else:
>             self._cache[ key ] = cached
> 
> in _cache_miss2 and _cache_miss1. If this were done, _sequence could 
> probably be deleted as well.
> 
> I'm not very familiar with the numarray code yet, so it's quite possible 
> I'm missing something, but I'm willing to do more digging to fix this if 
> this turns out to not be sufficient.
> 

I ran into the same problem trying to port MA to numarray, and came up
with an identical work around.  

A fix like this will be part of numarray-0.8.

Todd
-- 
Todd Miller 			jmiller at stsci.edu
STSCI / ESS / SSB