数据如下,我想将第二列数值相同的个数统计出来,比如,第二列的3有1个,6有2个,12有5个,14有3个,我想相应的在左边一列依次生成1,2,2,5,5,5,5,5,3,3,3............等等
* Example generated by -dataex-. To install: ssc install dataex
clear
input int year float panel_id
2006 3
2004 6
2005 6
1998 12
1999 12
2000 12
2001 12
2002 12
2004 14
2005 14
2006 14
2003 15
2004 15
2005 15
2001 16
1998 17
1999 17
2000 17
2001 17
2002 17
2003 17
2004 17
2005 17
2006 17
1998 18
1999 18
2000 18
2001 18
2002 18
2003 18
end
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