I have an issue with np.maximum.outer: NotImplementedError. Is there a way around?

Question

I have a matrix like this:

mat = pd.DataFrame(
  data=[
    (1,0,0,0),
    (1,1,1,0),
    (0,0,1,0),
    (0,1,0,1),
    (1,0,1,0)],
    columns=[\'ct1\',\'ct2\',\