股权转让数据中,上市公司一年中发生不同日期股权转让交易,如何设定为面板数据??
数据结构如下所示:
code date_trade first tranprice num_tran
000004 2004-03-12 2004 2.2 7106805
000004 2011-06-14 2011 15.23 3600000
000004 2011-07-21 2011 12.65475 2023689
000006 2006-03-15 2006 6.02 1.33e+07
000006 2010-07-20 2010 5.52 3.46e+07
000006 2010-12-07 2010 7.1375 2.74e+07
000006 2012-03-26 2012 5.06 3.68e+07
000006 2014-12-10 2014 6.691 1.35e+08
000007 2014-09-27 2014 17.78 7814188
000008 2011-11-15 2011 11 890718
000008 2014-08-23 2014 8.68 3.41e+07
000009 2011-07-07 2011 17.19 1.22e+07
000010 2014-12-10 2014 7.726 6004500
000011 2005-04-05 2005 1.2041 3.80e+08
000012 2004-02-17 2004 2.98 8.72e+07
000012 2010-11-06 2010 16.985 3.18e+07
000014 2013-07-20 2013 9.144555 3.36e+07
000016 2004-08-31 2004 5.53 5.50e+07
000016 2004-11-24 2004 5.4 2.90e+07
000016 2007-11-24 2007 6.98 4.35e+07
000017 2006-11-24 2006 .315 6.51e+07
000017 2014-09-27 2014 7.787 1.27e+07
000018 2006-11-16 2006 2.3853 5.01e+07
000018 2014-04-12 2014 9.92 1956090
000019 2007-08-17 2007 8.63 7.64e+07
000019 2012-07-13 2012 8.7 4060000
000022 2012-12-29 2012 11.088 1.61e+08
000023 2012-10-12 2012 7.35 1406300
000023 2013-07-17 2013 6.7 1.00e+07
000030 2012-02-10 2012 4 6.38e+07
000030 2012-12-21 2012 8.08 3300000
000030 2014-12-09 2014 7.4 6.38e+07
000031 2005-01-05 2005 2.8188 2.78e+08
000034 2014-10-15 2014 7.23 3757391
000035 2004-12-06 2004 2.975 3.36e+07
000037 2008-08-27 2008 5.17 6.51e+07
000037 2014-10-23 2014 3.712 3.09e+07
000038 2007-11-27 2007 4 1.00e+07
000038 2010-04-07 2010 9.92 1812150
000039 2004-08-20 2004 6.4531 1.64e+08
000040 2005-12-19 2005 1.1 2.57e+07
000040 2005-12-31 2005 3.2 1.82e+07
000042 2004-05-11 2004 6.56 6.70e+07
000042 2008-08-26 2008 9.69 4.48e+07
000042 2011-08-29 2011 19.755 6496371
000042 2012-02-08 2012 14.02 1.69e+07
000042 2013-02-05 2013 28.8 4.73e+07
000042 2013-11-07 2013 24 1.08e+07
000042 2013-12-10 2013 25.37 1.10e+07
000043 2005-01-21 2005 2.8 1.43e+07
000043 2008-01-29 2008 20 6.18e+07
000043 2012-10-23 2012 5.4 1.25e+07
000043 2013-11-20 2013 6.303 7216548
000046 2005-03-22 2005 3.5 8.25e+07
000046 2011-05-25 2011 9.7 4.12e+07
000046 2011-05-28 2011 9.3 3.74e+07
000048 2010-04-14 2010 5.3 7000000
000048 2013-06-20 2013 8.35 3.28e+07
000049 2013-05-23 2013 47.89 2213406
不能直接用 xtset code first。如何解决?? 谢谢