shanxuezhengxin 发表于 2014-12-23 10:43 
取滞后的时候,不是时间序列也行的把。比如我设定一变量X为: 123456789101112,然后运行命令L.X,应该得 ...
lag 是时间序列里的命令~
Time-series varlists are a variation on varlists of existing variables. When a command allows a time-series varlist, you may include time-series operators. For instance, L.gnp
refers to the lagged value of variable gnp. The time-series operators are
Operator Meaning
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L. lag (x_t-1)
L2. 2-period lag (x_t-2)
...
F. lead (x_t+1)
F2. 2-period lead (x_t+2)
...
D. difference (x_t - x_t-1)
D2. difference of difference (x_t - 2x_t-1 + x_t-2)
...
S. "seasonal" difference (x_t - x_t-1)
S2. lag-2 (seasonal) difference (x_t - x_t-2)
...
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