Hi, I´m doing a homework for my college. I have a sheet with regions, years and income. I need to group all the income of North of 2011. When I try to make a varaible with two categories, the RStudio say to me that´s impossible! Someone knows how I can solve this problem?
Thank you so much.
(Sorry for my bad English, it´s my second language.)
I try to do this:
The sheet that I have is a .RData