Can't create large multidimensional array in BLZ

[FrancescAlted]

[Adapted from https://github.com/Blosc/bcolz/issues/25]

With Numpy I can do something like this:

foo = np.zeros([ 2 ] * 20)

And get an ndarray with the corresponding shape. I can then:

ac = blz.barray(foo)

To get a barray object. Great. But I'm playing around with blaze.blz because I want to use array sizes that are larger than could otherwise fit in memory, and [2] * 20 is an easy shape for Numpy to handle, so for me it's a baseline of sorts.

Looking to explore the capabilities of blze.blz, I try to create the object directly, without the intermediate Numpy step:

ac = blz.zeros([2] * 20)

But I get an error:

In [11]: blz.zeros([2]*20)
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-11-32ca191bdff9> in <module>()
----> 1 blz.zeros([2]*20)

/home/faltet/software/blz/blz/bfuncs.pyc in zeros(shape, dtype, **kwargs)
    239     """
    240     dtype = np.dtype(dtype)
--> 241     return fill(shape=shape, dflt=np.zeros((), dtype), dtype=dtype, **kwargs)
    242 
    243 

/home/faltet/software/blz/blz/bfuncs.pyc in fill(shape, dflt, dtype, **kwargs)
    203     # Then fill it
    204     # We need an array for the defaults so as to keep the atom info
--> 205     dflt = np.array(obj.dflt, dtype=dtype)
    206     # Making strides=(0,) below is a trick to create the array fast and
    207     # without memory consumption

ValueError: number of dimensions must be within [0, 32]

Which leads me to wonder: is something like this possible using blz?

[FrancescAlted]

Yes, this is a problem with the size of the defaults that are too large for the multidimensional case. This should be fixed.