association_rules new metrics

[mikaelmv]

Hi,

It would be very beneficial to add couple fundamental metrics to association_rules. These are "Kulczynski metric" and "Imbalance Ratio" which provide the user with the most interesting patterns in consideration of null-invariance and itemsets' imbalance.

Their implementation is also very straightforward as its built on top of confidence and support.

Thank you,

[rasbt]

I agree, having additional metrics would be nice.