A numpy array view of the data array.
Changing the elements of the returned view changes the data array.
Examples
>>> a = f.varray
>>> type(a)
<type 'numpy.ndarray'>
>>> a
array([0, 1, 2, 3, 4])
>>> a[0] = 999
>>> f.varray
array([999, 1, 2, 3, 4])