Add error message for complex signals
Currently passing a complex HyperSpy signal to am.get_feature_separation
results in a very non-intuitive error message.
This should give a better error message, showing users how to "convert" the data to a non-complex signal.
Should also check:
-
Sublattice init -
Atom_Lattice init -
Quantitative STEM functions? Integrate? -
am.get_atom_positions