Here's a one-liner: In [31]: x=np.arange(-8,8) In [32]: x Out[32]: array([-8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7]) In [33]: 1&(x[:,np.newaxis]/2**np.arange(3,-1,-1)) Out[33]: array([[1, 0, 0, 0], [1, 0, 0, 1], [1, 0, 1, 0], [1, 0, 1, 1], [1, 1, 0, 0], [1, 1, 0, 1], [1, 1, 1, 0], [1, 1, 1, 1], [0, 0, 0, 0], [0, 0, 0, 1], [0, 0, 1, 0], [0, 0, 1, 1], [0, 1, 0, 0], [0, 1, 0, 1], [0, 1, 1, 0], [0, 1, 1, 1]]) On Mon, May 16, 2011 at 4:04 PM, Nikolas Tautenhahn wrote:

Hi,

...

Here

http://code.google.com/p/pylibtiff/source/browse/#svn%2Ftrunk%2Flibtiff%2Fbi...

you can find bitarray with numpy support.

Thanks, that looks promising - to get a numpy array, I need to do

numpy.array(bitarray.bitarray(numpy.binary_repr(i, l)))

for an integer i and l with i < 2**l, right?

best regards, Nik _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion

On Tue, May 17, 2011 at 8:05 AM, Pearu Peterson wrote:

On Tue, May 17, 2011 at 12:04 AM, Nikolas Tautenhahn wrote:

...

Hi,

...

Here

http://code.google.com/p/pylibtiff/source/browse/#svn%2Ftrunk%2Flibtiff%2Fbi...

...

you can find bitarray with numpy support.

Thanks, that looks promising - to get a numpy array, I need to do

numpy.array(bitarray.bitarray(numpy.binary_repr(i, l)))

for an integer i and l with i < 2**l, right?

If l < 64 and little endian is assumed then you can use the

fromword(i, l)

method:

...

...

...

from libtiff import bitarray barr = bitarray.bitarray(0, 'little') barr.fromword(3,4) barr bitarray('1100')

that will append 4 bits of the value 3 to the bitarray barr.

...

...

numpy.array(barr) array([ True, True, False, False], dtype=bool)

to complete the example... Pearu

Also check out various bitarray `to*` and `from*` methods.

HTH, Pearu