Hi

Out of curiosity, how do you submit your NONMEM jobs (eg, which command)?

Sebastien

Regeneron - Internal
________________________________
From: [email protected] <[email protected]> on behalf of 
Sebastiaan Sassen <[email protected]>
Sent: Wednesday, March 18, 2026 5:57 AM
To: [email protected] <[email protected]>
Subject: [External] [NMusers] Problem with initial values of the omega matrix 
with nonmem 7.6

Dear colleagues, I ran into a problem with the omega matrix in nonmem 7. 6 for 
a model I received (simple FOCE+I advan3 trans4 nothing special). In the model 
file it is specified like this (I tried different notations as simple decimals, 
scientific

Dear colleagues,

I ran into a problem with the omega matrix in nonmem 7.6 for a model I received 
(simple FOCE+I advan3 trans4 nothing special).

In the model file it is specified like this (I tried different notations as 
simple decimals, scientific notation etc. to no avail):

$OMEGA BLOCK(3)
  0.107                ; CL
   0.48E-1 0.11           ; V1
   0.42E-1 0.56E-1 0.084  ; V2


However, with nonmem 7.6 I get a problem with the initial estimates of omega. 
If I look at the list file I see that it is due to my omega block, which makes 
sense as the correlations between these values used as initial values of etas 
are not valid (outside of -1,1). However, these initial estimates are not the 
ones I provided. Compare this to the same exact model ran on nonmem 7.4.4. Here 
the initial omega estimates are as described in the model and it runs well.

Even in a clean folder without any files other than the dataset (csv) and the 
model file (mod).
Am I doing something wrong or is this something else?

Nonmem 7.6:

INITIAL ESTIMATE OF OMEGA HAS A NONZERO BLOCK WHICH IS NUMERICALLY NOT POSITIVE 
DEFINITE

0INITIAL ESTIMATE OF OMEGA:
 BLOCK SET NO.   BLOCK                                                          
          FIXED
        1                                                                       
            NO
                  0.1000E+01
                  0.4000E+01   0.1000E+01
                  0.4000E+01   0.5000E+01   0.8000E+01


Compared to nonmem 7.4.4, which seems to do this correctly:
    
0INITIAL ESTIMATE OF OMEGA:
 BLOCK SET NO.   BLOCK                                                          
          FIXED
        1                                                                       
            NO
                  0.1070E+00
                  0.4800E-01   0.1100E+00
                  0.4200E-01   0.5600E-01   0.8400E-01

Best regards,

Sebastiaan

******************************************************************** 
This e-mail and any attachment hereto, is intended only for use by the 
addressee(s) named above and may contain legally privileged and/or confidential 
information. If you are not the intended recipient of this e-mail, any 
dissemination, distribution or copying of this email, or any attachment hereto, 
is strictly prohibited. If you receive this email in error please immediately 
notify me by return electronic mail and permanently delete this email and any 
attachment hereto, any copy of this e-mail and of any such attachment, and any 
printout thereof. Finally, please note that only authorized representatives of 
Regeneron Pharmaceuticals, Inc. have the power and authority to enter into 
business dealings with any third party. 
********************************************************************

Reply via email to