From: "Xiao, Alan" alan_xiao@merck.com
Subject: [NMusers] erros messages related to data file and/or NONMEM I/O 
Date: Wed, April 27, 2005 4:45 pm 

Hello Friends,

 

Could anyone help me debug this message in the beginning of a NONMEM report file?

========================================================

.........

0ERROR SUBROUTINE CALLED WITH EVERY EVENT RECORD.

1

MONITORING OF SEARCH:

0PROGRAM TERMINATED BY OBJ

ERROR IN ELS WITH INDIVIDUAL 1127 ID=0.00000000E+00

VAR-COV OF DATA FROM INDIVIDUAL RECORD ESTIMATED TO BE SINGULAR

MESSAGE ISSUED FROM ESTIMATION STEP

AT INITIAL OBJ. FUNCTION EVALUATION

========================================================================

The individual 1127 is the last one in the data file and I have no idea how this ID=0000
came from. I checked my data file, which was created via SAS 8.2, but nothing useful was
found. I used the same SAS program to generate many different data files only 2 out
of 8 files had this problem.


Thanks,

Alan
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From:  "Xiao, Alan" alan_xiao@merck.com
Subject: [NMusers] RE: erros messages related to data file and/or NONMEM I/O 
Date: Thu, April 28, 2005 10:51 am 

Hello,
 
Thank all those friends who kindly responded to my last email. It looks like
the discussion posted in the following link is relevant - special thanks to
Leonid for forwarding this to me. 
 
http://www.cognigencorp.com/nonmem/nm/99oct041996.html
 
Based on this discussion, I slightly modified my model - still use my original
proportional residual model but add a very small additive error model (0.000001)
for test, the problem is gone. 
 
Now, my question for your discussion is that why this happened to a data file (with a
limited dose range) but not others (e.g. a data file with the full dose range) even
both data files start with a concentration record (predose, but different ID) followed
by a dosing record - I used calendar date and clock time. Or is there anything else I'm missing? 
 
 
Alan 
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