- 如何生成四大虛擬變量
- 將各四大分別識別出來
**生成四大虛擬變量
tab audfirm
gen big4 = regexm(audfirm,"安永|德勤|畢馬威|普華") if audfirm != ""
**將各四大分別識別出來
gen ey = regexm(audfirm,"安永") if audfirm != ""
gen dtt = regexm(audfirm,"德勤") if audfirm != ""
gen kpmg = regexm(audfirm,"畢馬威") if audfirm != ""
gen pwc = regexm(audfirm,"普華永道") if audfirm != ""
tab yr big4,r //row :report relative frequency within its row of each cell