Indexing error leads to crash when maximum of G is the first value

[OskarHofmann]

I wanted to run the script on my data but always got the error
"ValueError: zero-size array to reduction operation minimum which has no identity" in line 107 of ampd.py

The issue is that the largest value in G (for my data) is the first one and thus
l_scale = np.argmax(G)
leads to l_scale = 0

In line 107 the array LSM is reduced to
LSM[0:l_scale, :]
But as l_scale = 0 this leads to an empty array and an error when trying to to use np.min on it.

I think line 107 should be
pks_logical = np.min(LSM[0:l_scale+1, :], axis=0)

[OskarHofmann]

Issue is already mentioned in Issue #6