Re: what's the meaning of Bond in CORI algorithm
Date: May 24, 2020 04:29PM
Hi Xiaowei,
The CORI algorithm is an algorithm to find sets of values that do not appear very frequently together but have a high correlation.
The SPMF documentation of CORI is here:
http://www.philippe-fournier-viger.com/spmf/CORI.php
It contains some example.
Also, here is the link to the paper:
http://www.philippe-fournier-viger.com/spmf/cori.pdf
The idea of the bond measure is the following.
Let's say that you have a set of items {a,b,c,d}.
The BOND will be how many transactions (records) contain a,b,c,d together in the database divided by how many transactions contains at least one item from {a,b,c,d}.
If the BOND is equal to 1, it means that {a,b,c,d} always appear together. In other words, if you have a, then you also have b,c,d. Or if you have b, you always have a, c, d. Or if you have c, then you always have a b d. And if you have d, you always have a b c.
IF the BOND is equal to 0, it means that {a,b,c,d} never appear together.
So in general, a BOND closer to 1 means a higher correlation, while a BOND closer to zero means a lower correlation.
That is the main idea.
If something else is not clear, you can ask.
Best regards,