请哪位高手帮忙解读下这个forvalues命令是在做一件什么事?看不大懂这个命令,谢谢了!
xtdes
gen b = .
forvalues i=1/438{
qui reg tl size tang tobin if code_123==`i'
replace b = _b[tobin] in `i'
}
gen i = _n
browse i b in 1/20
gen b = .
forvalues i=1/438{ //循环438次,i 从 1 到438
qui reg tl size tang tobin if code_123==`i' //在所有code_123为i 的观测值中,做regression
replace b = _b[tobin] in `i' //得到tobin的系数, 并存为b,但只是在所有code_123为i 的observations 中
}
gen i = _n
browse i b in 1/20