can someone pls help me, I am having a crisis!
i have a model that i want to fit, that is,
yield=alpha_variety + gammaclay_i +delta(rainfall-mean(rainfall)) + error
where there are 4 varieties of wheat labelled A,B,C,D.
I need help on how to input an indicator variable which is clay_i that takes value 1 if any of those 4 varieties of wheat are grown in clay soil and 0, otherwise.