[Numpy-discussion] how add new attribute to a numpy array object ?

[Kevin Jacobs <jacobs@bioinformed.com>]

On 7/22/06, Sebastian Haase <haase at msg.ucsf.edu> wrote:
>
> Normally I could do
> class B(N.ndarray):
>     pass
> a=N.arange(10)
> a.__class__ = B
>
> BUT I get this error:
> #>>> a.__class__ = B
> Traceback (most recent call last):
>    File "<input>", line 1, in ?
> TypeError: __class__ assignment: only for heap types
>
> What is a "heap type" ? Why ?  How can I do what I want ?



Assigning to __class__ makes sense for objects that allocate a dictionary
for storage of attributes or have slots allocated to hold the values.  The
heap type error is due to a missing flag in the class definition and could
be corrected.  However, it may not be the best thing to do.  Calling
B(array) is certainly safer, although a bit more expensive.

-Kevin
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://projects.scipy.org/pipermail/numpy-discussion/attachments/20060723/20de75dd/attachment.html