Also, note PEP8 style guidelines -- this one's longer than 80 char. This is why I cut off my example line as:
```
    idx = np.where(np.all(np.logical_and(np.diff(data, axis=1) != 0,
                                         data[:, 1:] > 0), axis=0))[0]        
```
Note the "< 80 char"-ness, and the alignment between arguments inside the `np.logical_and()` -- these were done to conform to PEP8.