17:29:03: Q1 what is the dim of J?
17:33:15: Q2 what is the dim of H?
17:34:57: Q3 what is dim of (th - th_0 )^T?
17:36:37: Q4 dim of AB?
17:39:15: Q5 what is grad of the first term?
17:39:53: Q6 what is grad of the second term?