- * Example generated by -dataex-. To install: ssc install dataex
- clear
- input byte id int date byte dum_date
- 1 2000 0
- 1 2001 0
- 1 2002 0
- 1 2003 0
- 1 2004 0
- 1 2005 0
- 1 2006 0
- 2 2000 0
- 2 2001 0
- 2 2002 0
- 2 2003 0
- 2 2004 0
- 2 2005 0
- 2 2006 0
- 3 2000 0
- 3 2001 0
- 3 2002 0
- 3 2003 0
- 3 2004 0
- 3 2005 0
- 3 2006 0
- 4 2000 0
- 4 2001 0
- 4 2002 0
- 4 2003 0
- 4 2004 0
- 4 2005 0
- 4 2006 0
- end
复制代码
forvalues v =1(1)4 {
dis `v'
forvalues year = 2000/2006 {
replace dum_date=1 if date >= 2001+`v' & id == `v'
}
}
结果如下:
- * Example generated by -dataex-. To install: ssc install dataex
- clear
- input byte id int date byte dum_date
- 1 2000 0
- 1 2001 0
- 1 2002 1
- 1 2003 1
- 1 2004 1
- 1 2005 1
- 1 2006 1
- 2 2000 0
- 2 2001 0
- 2 2002 0
- 2 2003 1
- 2 2004 1
- 2 2005 1
- 2 2006 1
- 3 2000 0
- 3 2001 0
- 3 2002 0
- 3 2003 0
- 3 2004 1
- 3 2005 1
- 3 2006 1
- 4 2000 0
- 4 2001 0
- 4 2002 0
- 4 2003 0
- 4 2004 0
- 4 2005 1
- 4 2006 1
- end
复制代码