Practical Predictive Analytics

Inspecting the transaction file

Once the data has been coerced to transaction form, we can use the inspect function to examine the data.

When inspecting transaction files, you do not use normal print, or head functions directly, since the objects are in sparse format. You use an inspect() function instead.

If you happen to have the tm package loaded (which we will use later), you must preface inspect with arules::inspect, since there is also an inspect function in the tm package that serves a different purpose.

If you run an inspect command on the first five records, you can see that the data is in basket format, that is, each invoice shows the itemsets, delimited by {}, that are associated with each invoice:

 arules::inspect(trans4[1:5]) ...