Writes np.sum(a**2,axis=0) into s

def square_and_sum(a, s):
    """
    Writes np.sum(a**2,axis=0) into s
    """
    cmin, cmax = thread_partition_array(a)
    map_noreturn(asqs, [(a, s, cmin[i], cmax[i]) for i in xrange(len(cmax))])
    return a