我有这个数据框：
> head(merged.tables)
Store DayOfWeek Date Sales Customers Open Promo StateHoliday SchoolHoliday StoreType
1 1 5 2015-07-31 5263 555 1 1 0 1 c
2 1 6 2013-01-12 4952 646 1 0 0 0 c
3 1 5 2014-01-03 4190 552 1 0 0 1 c
4 1 3 2014-12-03 6454 695 1 1 0 0 c
5 1 3 2013-11-13 3310 464 1 0 0 0 c
6 1 7 2013-10-27 0 0 0 0 0 0 c
Assortment …