Data structure to panel

#1
Hi,

I have very detailed panel data about sales - that means for each week and store I have data about approx. 80 products - their price and volume of sales. But my data have this structure

week - store - item - price - sales
1 - 1 - 1 - 5 - 3
1 - 1 - 2 - 6 - 2
1 - 2 - 1 - 5 - 4
1 - 2 - 2 - 7 - 0
2 - 1 - 1 - 6 - 2
2 - 1 - 2 - ..
2 - 2 - 1 - ..
2 - 2 - 2 - ..
3 - ...

if I try xtset command, stata tells me "repeated time values within panel" which makes sence since there are data about multiple products.

It seems to me that the right thing to do here would be to set the products as separate variables (so to have price of item1, price of item2, sales of item1, sales of item2, ...). How do I change the data structure to be able to use panel tools in Stata?
Or is there some way to tell Stata some more info about the panel data so that I could be using xt functions? My aim here is a fixed-effects panel regression...

Thank you for any tips!
Tom
 
#2
consearning changing data structure from long to wide, the command "reshape" did the trick....but Im stil thinking, where it was the right move given that now I have 80 variables with price and 80 with quantity... :-/