Hi Mark,
Very interesting point. In general, your logic about why the covariance
step doesn't matter in the bootstrapping case makes sense to me.
However, I have some questions about why such a conclusion was reached.
My questions are: 1. how many data sets are bootstrapped, 2. among them,
what's
Hi Varsha,
You may need to fix some of the OMEGAs. During a recent simulation
exercise, I used the true model to fit data randomly generated from a
model and the same message showed up. I fixed the OMEGA for one
parameter which the data has limited information on and the covariance
step became suc
Dear NONMEM Users,
I have a study where I'd like to predict AUC based on 2~3 trough
concentrations. There are about 500 subjects and I intend to predict
drug concentration for 560 time points for each subject (10 time
points/day * 56 days). The EBE for model parameters for each individual
have be
it worked.
Thanks for your suggestions of adding an AUC compartment, this is
certainly something new I learned.
Kind regards,
Yaming
-Original Message-
From: Johan Wallin [mailto:wallin_jo...@lilly.com]
Sent: Thursday, February 18, 2010 9:23 AM
To: Hang, Yaming
Subject: Re: [NMusers] P
Hi Hong,
Other approaches I can think of are:
1.to plot the EBE of CL vs. different GVHD categories to determine
whether you need a different parameter for each level or indeed you can
(and how to) combine several groups together;
2.since your GVHD variable is an ordinal categorical variable inste
Hi Leonid,
Strictly speaking, when you use parameterization THETA(*)*ETA()
(actually I like this trick as well), you have to constraint THETA(*) to
be either positive or negative, otherwise this model has identifiability
issue. So still, the hypothesis shall be one-sided.
Thanks,
Yaming
-O
