su income if inocme!=.,d gen newincome=((income<r(p25))|(income>r(p25) & income<r(p75))|(income>=r(p75)))+(income>r(p25) & income<r(p75)|(income>=r(p75)))+(inome>=r(p75)) if income!=.
如果觉得第二步太长
可以考虑像sungmoo一样的作法
gen newincome=(income<r(p25))+(income>=r(p25) & income<r(p75))*2+(income>=r(p75))*3