problem indexing in process.py sorted_matrix & sorted_lev() doesn't exist

[emilienschultz]

There is a problem in the use and the definition of sorted_lev in the notebook of Analyze senders

First sorted_lev doesn't exist and it seems to be sorted_matrix now

Then there is a problem with sorted_matrix where new_df is defined without new_columns defined.

new_df = df.reindex(index=new_columns, columns=new_columns)