操作方法
gen where ="D" if foreign=="Domestic":origin replace where ="F" if foreign=="Foreign":origin 如果foreign的值为domestic则where的值为D,否则where的值为F
显示自定义变量. list make foreign where
显示where变量的详细信息
定义model变量和modelwhere变量 gen model =usubstr(make,ustrpos(make,"")+1,.) gen modelwhere =model +" " + where
显示model变量和modelwhere变量的值。 list make where model modelwhere