Right, thanks for pointing that out. I reused the exercise here from above, perhaps it should be:

```
In [6]: np.diag([2,3,4,5,6], k=-1)
Out[6]: 
array([[0, 0, 0, 0, 0, 0],
       [2, 0, 0, 0, 0, 0],
       [0, 3, 0, 0, 0, 0],
       [0, 0, 4, 0, 0, 0],
       [0, 0, 0, 5, 0, 0],
       [0, 0, 0, 0, 6, 0]])
```

I'll dig through the logs and figure the the original intention.