检验结果:
Type 1: no drift no trend
lag ADF p.value
[1,] 0 -13.6 0.01
[2,] 1 -18.7 0.01
[3,] 2 -3.4 0.01
Type 2: with drift no trend
lag ADF p.value
[1,] 0 -12.71 0.0100
[2,] 1 -17.52 0.0100
[3,] 2 -2.85 0.0697
Type 3: with drift and trend
lag ADF p.value
[1,] 0 -11.57 0.010
[2,] 1 -16.78 0.010
[3,] 2 -2.06 0.533
Note: in fact, p.value = 0.01 means p.value <= 0.01