Changing array dimensions

>>> a = array([0, 1.2, 4, -9.1, 5, 8])
>>> a.shape = (2,3)       # turn a into a 2x3 matrix
>>> print a
[[ 0.   1.2  4. ]
 [-9.1  5.   8. ]]
>>> a.size
6
>>> a.shape = (a.size,)   # turn a into a vector of length 6 again
>>> a.shape
(6,)
>>> print a
[ 0.   1.2  4.  -9.1  5.   8. ]
>>> a = a.reshape(2,3)    # same effect as setting a.shape
>>> a.shape
(2, 3)