请问大神们,如果对每个观测值只想使用这条观测值前面的20条观测值为样本进行回归应该怎么操作呢?reg里面好像没有提供相关的option,搜索了一下已有的帖子,感觉也都不是我想要实现的效果。如果使用statsby里面的basepop()不知道是否可行,这个命令有人用过吗?下面截了前两个id数据样本,整个数据集一共有2万多个id。
- * Example generated by -dataex-. To install: ssc install dataex
- clear
- input float(id dif stkrt mktrt)
- 1 -36 -.037681 .002137
- 1 -35 .024849 .035635
- 1 -32 .054372 .024336
- 1 -31 .000697 -.034699
- 1 -30 -.02507 -.04453
- 1 -29 -.039286 .013929
- 1 -28 .013383 .024308
- 1 -25 .09978 .029733
- 1 -23 .010674 .001857
- 1 -22 -.089109 -.057169
- 1 -18 .014493 .015424
- 1 -17 -.035 -.004403
- 1 -16 .097705 .065896
- 1 -15 .021578 .008718
- 1 -14 -.010561 -.007622
- 1 -11 -.02068 -.040027
- 1 -10 .01158 .020552
- 1 -9 -.012795 -.007518
- 1 -8 .031378 -.000543
- 1 -7 -.019841 -.006132
- 1 -4 .029015 .015938
- 1 -3 .041967 .036093
- 1 -2 -.011328 .006781
- 1 -1 .005092 .021895
- 1 0 -.029132 -.002316
- 1 3 .017613 .024565
- 1 4 .004487 .006408
- 1 5 .008296 -.022659
- 1 6 .04557 .03085
- 1 7 -.00908 .008459
- 2 -35 -.020159 -.002642
- 2 -34 -.006234 .010208
- 2 -33 .016311 .015739
- 2 -32 .031481 .007674
- 2 -31 .002394 -.004922
- 2 -27 -.00597 .00547
- 2 -26 -.035435 -.037495
- 2 -25 .018057 .016863
- 2 -24 .015902 .032386
- 2 -21 .007827 .021015
- 2 -20 -.004779 .011544
- 2 -19 -.021609 .007729
- 2 -18 .003067 .001614
- 2 -17 -.028746 -.013181
- 2 -14 .016373 .024094
- 2 -13 -.021685 -.008458
- 2 -12 -.032932 -.041709
- 2 -11 -.003929 .006553
- 2 -10 .00789 -.008479
- 2 -7 -.011742 -.029351
- 2 -6 .029703 .005429
- 2 -5 .058333 .031641
- 2 -4 -.011508 .009435
- 2 0 .026961 .034658
- 2 1 .001193 .007043
- 2 2 .02801 .01441
- 2 3 .04058 -.001959
- 2 4 .012813 .006726
- 2 7 -.029153 -.028217
- 2 8 .014164 .024305
- end
复制代码