New script to test how accurate the linear regression is
New help function AddFirstPrice
New script to group customers and estimate demand
Fixed ill-defined min.week and max.week bug
Moved code into new function GroupCookies
Added should.print argument
Rewrote using split-apply-combine, to compute new fields
Add column "item" to output
Fixed missing "the.item" bug in AddFirstPrice
The set of good items from running 2013-09-29
Added missing group.size argument
New function pre-computes the groups for a set of items