Hi,
I have a challenging PD model that I recently completed working on. In
some of the runs, I got a likelihood value when I think NONMEM should
have aborted without providing the likelihood. The complete story is below.
I was using SAEM, and during some of the runs, I got the following error
at the bottom of the .lst file:
0PROGRAM TERMINATED BY FNLETA
0PRED EXIT CODE = 1
0INDIVIDUAL NO. 1 ID= 1.00000000000000E+00 (WITHIN-INDIVIDUAL)
DATA REC NO. 2
THETA=
NaN NaN 4.75E+00 -3.91E+00 -3.30E+00 -3.30E+00
NaN 3.00E-01 -1.00E+00 0.00E+00
NaN NaN NaN -2.00E+00 0.00E+00 NaN
NaN NaN -2.00E+00 0.00E+00
NaN 0.00E+00 0.00E+00 0.00E+00 0.00E+00
OCCURS DURING SEARCH FOR ETA AT INITIAL VALUE, ETA=0
F OR DERIVATIVE RETURNED BY PRED IS INFINITE (INF) OR NOT A NUMBER (NAN).
0PROGRAM TERMINATED BY FNLETA
MESSAGE ISSUED FROM TABLE STEP
#CPUT: Total CPU Time in Seconds, 4091.372
Stop Time:
Fri Jul 1 21:32:38 UTC 2016
This is expected due to the model convergence properties. At the point
I ran this model during model development, I was still developing my
parameter and calculation protections. But, the issues is that NONMEM
kept running to the end of the model through all SAEM burn-in and
accumulation iterations:
Stochastic/Burn-in Mode
iteration -1000 SAEMOBJ= 11412.435172982327
iteration -999 SAEMOBJ= 0.0000000000000000
iteration -998 SAEMOBJ= 0.0000000000000000
(etc.)
The continued run could potentially be expected because my $ESTIMATION
record specified NOABORT:
$ESTIMATION SIGL=9 NSIG=3 NOABORT METHOD=SAEM INTERACTION LAPLACIAN
NBURN=1000 CTYPE=3 GRD=TS(1-2) NITER=10000 IACCEPT=0.2
ISAMPLE=5 PRINT=1 NOPRIOR=1 SEED=5 MSFO=run15.msf
$COVARIANCE PRINT=E
But the real issue is that I got a SAEM final value of the likelihood
function which should have been NAN if reported at all:
************************************************************************************************************************
******************** ********************
******************** STOCHASTIC APPROXIMATION
EXPECTATION-MAXIMIZATION (NO PRIOR) ********************
#OBJT:************** FINAL VALUE OF LIKELIHOOD
FUNCTION ********************
******************** ********************
************************************************************************************************************************
#OBJV:******************************************** 0.000
**************************************************
What are peoples' thoughts? Is this expected because of the NOABORT (or
another reason) or should it be updated in a future NONMEM version?
Thanks,
Bill
------------------------------------------------------------------------
Human Predictions Logo <http://www.humanpredictions.com>*William S.
Denney, PhD*
Chief Scientist, Human Predictions LLC
+1-617-899-8123
wden...@humanpredictions.com
This e-mail communication is confidential and is intended only for the
individual(s) or entity named above and others who have been
specifically authorized to receive it. If you are not the intended
recipient, please do not read, copy, use or disclose the contents of
this communication to others. Please notify the sender that you have
received this e-mail in error by replying to the e-mail or by calling
+1-617-899-8123. Please then delete the e-mail and any copies of it.
Thank you.
