[Cython] buffer types as members of extension types?

[Norbert Nemec]

Dag Sverre Seljebotn wrote:
>
>> Is there a workaround that allows me to store and efficiently access buffer data in an extension type?
>>     
>
> Is this what you are referring to which is too slow?:
>
> 1) Store it as plain numpy.ndarray
> 2) Copy it to numpy.ndarray[numpy.float_t] inside the local function 
> before processing
>   
The core routine is called very often, each time, the data is accessed 
just once. Doing the conversion once for every call would therefore not 
gain me anything... :-(

> If that is too slow as well, I'm afraid the only solution right now is 
> to store it as numpy.ndarray and access the data field (i.e. 
> self.data.data), casted to numpy.float_t*. You must then make sure you 
> work with a contiguous array:
>
>      if not data.flags['C_CONTIGUOUS']:
>          data = data.copy()
>      self.data = data
>   
Ok, that's ugly, but it should work. The array is created within the 
class, so I have full control. I could then just store an additional 
class member of pointer type and use that to access the data.

Thanks for the help!