COND LAPLACE LIKELIHOOD
Dear nmusers,
Has anybody seen the following error message from NONMEM:
"CONDITIONAL LIKELIHOOD SET TO NEGATIVE VALUE
WITH INDIVIDUAL 2 (IN INDIVIDUAL RECORD ORDERING), DATA RECORD 13"?
What does it mean?
I am trying to use conditional lapalacian likelihood method to generate a proportional odds model dealing with categorical PD data. Here is a little piece of my data set:
SUBJ TIME AMT EVID II ADDL DV CL V MDV
2 0 . 0 . . 0 4.12 63 0
2 0 1 1 1 20 . 4.12 63 1
2 0.005 . 2 . . . 4.12 63 1
2 0.01 . 2 . . . 4.12 63 1
.
.
.
2 12 . 0 . . 0 4.12 63 0
2 13 . 0 . . 1 4.12 63 0
.
.
.
But I don't think the problem exists in the data set because I tried deleting the rows indicated in the error message, but the exactly same message still came out and NONMEM stopped running. I have no idea what's the problem for my model.
Thanks in advance,
Tianli