|
刚刚自己也reg了一下,得到的系数是均值,reg后面只有一个变量可能是为了求均值和标准差
. reg CAR_date if dif==0
Source | SS df MS Number of obs = 2,224
-------------+---------------------------------- F(0, 2223) = 0.00
Model | 0 0 . Prob > F = .
Residual | 149.984667 2,223 .067469486 R-squared = 0.0000
-------------+---------------------------------- Adj R-squared = 0.0000
Total | 149.984667 2,223 .067469486 Root MSE = .25975
------------------------------------------------------------------------------
CAR_date | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
_cons | .0372368 .0055079 6.76 0.000 .0264356 .048038
------------------------------------------------------------------------------
. sum CAR_date if dif==0
Variable | Obs Mean Std. Dev. Min Max
-------------+---------------------------------------------------------
CAR_date | 2,224 .0372368 .2597489 -1.30879 2.330122
|