arlionn 发表于 2008-9-19 14:38
* 试一下这个:sysuse auto, clearreg price wei lenpredictnl yhat = _b[_cons] + _b[weight]*wei + ...
再问一个问题,为什么我用自己的数据就不能画出来呢? 它说我的lb ub不存在??!!
如下
use "C:\Program Files\stata11(有教程版)\do\Model2.dta", clear
. reg lnarrivals lnarrivals
Source | SS df MS Number of obs = 255
-------------+------------------------------ F( 1, 253) = .
Model | 348.200868 1 348.200868 Prob > F = .
Residual | 0 253 0 R-squared = 1.0000
-------------+------------------------------ Adj R-squared = 1.0000
Total | 348.200868 254 1.37086956 Root MSE = 0
------------------------------------------------------------------------------
lnarrivals | Coef. Std. Err. t P>|t| [95% Conf. Interval]
-------------+----------------------------------------------------------------
lnarrivals | 1 . . . . .
_cons | -3.55e-15 . . . . .
------------------------------------------------------------------------------
. predictnl yhat = -b[-cons]+-b[lnarrivals]*lnarrivals,ci(lb ub)
b not found
r(111);
求解啊