From:"Stephen Duffull"
Subject:[NMusers] BOV and BSV
Date:Mon, March 11, 2002 7:35 pm
Hi
Just a quick question about estimating BSV and BOV.
I have some data where I can get estimates of BOV but the estimates of BSV
for some of the parameters becomes essentially zero (< 1e-10) - ie all
parameter variability is thought to arise from BOV. If I delete the ETAs
from the code of those parameters for which NONMEM cannot estimate BSV then
the code does not minimise successfully - indeed seems to 'go off into
space'; however, if I fix the OMEGA elements to zero then it works fine. Is
it necessary for NONMEM to have BSV components for all parameters that it
wishes to estimate BOV for? I cannot think of a reason why this would be
so.
Thanks
Steve
PS I am not necessarily assuming that BSV is zero for those parameters for
which BSV cannot be estimated.
*****************************************
Stephen Duffull
School of Pharmacy
University of Queensland
Brisbane 4072
Australia
Tel +61 7 3365 8808
Fax +61 7 3365 1688
http://www.uq.edu.au/pharmacy/duffull.htm