我需要对相同年月(accper)的数据,按size的大小分为三组。数据是全部A股上市公司每月的stock return (rp)。
stkcd accper size rp
000001 2004-01 1.457e+10 .090482
000001 2004-02 1.627e+10 .116379
000001 2004-03 1.674e+10 .028958
000001 2004-04 1.465e+10 -.124765
000001 2004-05 1.511e+10 .031083
000001 2004-06 1.350e+10 -.106029
000001 2004-07 1.274e+10 -.056977
000001 2004-08 1.281e+10 .006165
000001 2004-09 1.281e+10 0
000001 2004-10 1.126e+10 -.121324
000001 2004-11 1.107e+10 -.016736
000001 2004-12 1.035e+10 -.065248
000001 2005-01 9.516e+09 -.080425
000001 2005-02 1.018e+10 .069307
000001 2005-03 8.181e+09 -.195988
000001 2005-04 9.736e+09 .190019
000001 2005-05 9.438e+09 -.030645
000001 2005-06 9.312e+09 -.013311
000001 2005-07 9.312e+09 0
000001 2005-08 9.783e+09 .05059
000001 2005-09 9.045e+09 -.075441
000001 2005-10 8.966e+09 -.008681
000001 2005-11 9.171e+09 .022767
000001 2005-12 9.642e+09 .05137
000001 2006-01 9.971e+09 .034202
000001 2006-02 1.074e+10 .077165
000001 2006-03 1.000e+10 -.068713
000001 2006-04 1.237e+10 .237049
000001 2006-05 1.379e+10 .114213
000001 2006-06 1.187e+10 -.138952
000001 2006-07 1.055e+10 -.111111
000001 2006-08 1.135e+10 .075893
000001 2006-09 1.281e+10 .128631
000001 2006-10 1.500e+10 .170343
000001 2006-11 1.986e+10 .324607
000001 2006-12 2.272e+10 .143874
000001 2007-01 3.669e+10 .322046
000001 2007-02 3.653e+10 -.004182
000001 2007-03 3.621e+10 -.008924
000001 2007-04 4.977e+10 .37447
000001 2007-05 5.502e+10 .105588
000001 2007-06 5.278e+10 .055417
000001 2007-07 6.948e+10 .316497
000001 2007-08 7.288e+10 .048855
000001 2007-09 7.667e+10 .052105
000001 2007-10 9.215e+10 .201851
000001 2007-11 6.919e+10 -.249116
000001 2007-12 7.403e+10 .069845
000001 2008-01 9.593e+10 -.137306
000001 2008-02 9.550e+10 -.004505
我想出来的命令是bys accper: gen g1 = cut(size), group(3)。
但是他一直提示unknown function cut(), 或者egen ... cut() may not be combined with by
请问各位大神我错在哪里。


雷达卡





京公网安备 11010802022788号







