Karina,
TOL=4 is on the low side for most models. A TOL=4 implies a SIGL<=4 and
SIGDIG=4/3 or 1.33.
This would mean that all of the final parameter estimates could have less than
2 significant digits.
(See Intro to NONMEM 7 guide section I.14 for further details about controlling the precision of the
gradient evaluation).
I typically use SIGDIG=3 with SIGL=9 and TOL=9 in NONMEM 7. For NONMEM 6, SIGL can not be specified
and I have not had much success with TOL values > 6.
Luann Phillips
Director, PK/PD
Cognigen Corporation
On 1/11/2013 12:56 PM, VegaVilla, Karina R (HSC) wrote:
Dear NMusers,
I have developed a model that has some rate constant estimates with very low
values, (i.e. 10E-05)
and I’m running NONMEM with TOL=4. Is that the appropriate approach? If not,
what would you suggest.
Thanks.
Karina R. Vega-Villa, Ph.D.
Postdoctoral Research Associate
