Increasing the number of variables to a explanatory covariates set

[luis gamboa]

I would like to estimate several linear regressions in which the explanatory set is increasing as follows.

reg y x z1
reg y x z1 z2
reg y x z1 z2 z3
...
reg y x z1 z2 z3.....z50

what I am firstly interested in is in showing that R2 is increasing as the number of variables is higher. So after each regression, I want to save the R2 coefficient
I tried to make a loop but it does not work:

[George Ford]

clear
set obs 1000
forv i = 1/50 {
    g z`i' = rnormal()
}
g y = rnormal()
matrix R = J(50,2,.)
matrix colnames R = r2 adj_r2
forv i = 1/50 {
    qui reg y z1-z`i'
    matrix R[`i',1] = e(r2)
    matrix R[`i',2] = e(r2)
}
matrix list R

[luis gamboa]

Thank you George. Your code was very helpful (I only change e(r2_adj) at the second column-matrix)

[George Ford]

Yup. Sorry for the error.