就是出现这样的Iteration 0:   log likelihood = -129676.31  (not concave)Iteration 1:   log likelihood = -128797.16  (not concave)
Iteration 2:   log likelihood = -128240.27  (not concave)
Iteration 3:   log likelihood = -127037.33  (not concave)
Iteration 4:   log likelihood = -126416.13  (not concave)
Iteration 5:   log likelihood =  -126205.7  (not concave)
Iteration 6:   log likelihood = -126050.11  (not concave)
Iteration 7:   log likelihood =  -126015.6  (not concave)
Iteration 8:   log likelihood = -125991.15  (not concave)
Iteration 9:   log likelihood = -125975.72  (not concave)
Iteration 10:  log likelihood = -125960.32  (not concave)
Iteration 11:  log likelihood = -125924.85  (not concave)
Iteration 12:  log likelihood = -125917.24  (not concave)