Explain better what the letter counts mean for sender/receiver

[lilimelgar]

One of the participants (Koen) asks:
"How did you make the list of names with sum(sender+receiver) for every name? It could be interesting to see the ratio sender/receiver. E.g., if the ratio is > 1, one sends more than receives, and if < 1, the opposite is true. If the ratio is > 50, you know the collection is biased, and probably only occurs in their own correspondence collection (in the case of Huygens, Grotius, etc.). Watch out for dividing by 0 if receiver is 0."

Take care of this in three steps:

• Explain/document better what the counts mean
• Add counts per letter besides counts per hits (this is also based on issue Correct explanation of number of letters vs number of records #1)
• Create code that counts the number of letters sent vs the number of letters received
• Consider if it's possible adding documentation (or a value) indicating possible bias in the collection according to Koen's suggestion (what he meant is that some catalogs have entered all the correspondence received by of one person). Need to gather requirements for this one.

[lilimelgar]

It's corrected, but Dirk should check before closing this.