R Programming By Example

The too-much-repeated-data problem

What variable do we still have in the sales data frame? Well, to phrase it in such a way as to make the problem very obvious, we still have the sales variables and the customer's variables. So, what might the problem be? Well, each time a customer makes a new purchase, we save her BIRTH_DATE, CLIENT_SINCE, GENDER, and STARS information again. What if a frequent customer has 100 different purchases with The Food Factory? Well, her information will be repeated 100 times! We need to fix that. How might we do it? We do the same thing we did before, separate things that are different. That's right. We create a separate data frame for the customer data, and we already know how to link the customers with the sales ...