From: laurent.nguyen@pierre-fabre.com
Subject: Scaled Transform Parameters
Date: Tue, 25 Sep 2001 18:08:43 +0200
Hi everybody,
Just a question about NONMEM outputs during the estimation step :
In NONMEM guides, it is reported that the values PARAMETERS plotted during
the estimation step correspond to scaled transform parameters (STP).
However, the exact operations performed to calculate these STPs are not
clearly described.
Is it possible, knowing the initial values and these parameters, to
recalculate the corresponding THETAs ,ETAs and SIGMA?
Could somebody help me to understand what are STPs, or where I can find
some clear explanations about?
Thanks
P.VARIOL
Scaled Transform Parameters
From: "Bachman, William" <bachmanw@globomax.com>
Subject: RE: Scaled Transform Parameters
Date: Tue, 25 Sep 2001 12:39:04 -0400
Although I don't know the particular algorithm used to scale the parameters,
the unscaled parameters can be obtained from the INTER file which is
produced when the MSF option is used on the $EST line. Of course, this is a
temporary file which is deleted at the end of the run. But then, at the end
of the run OUTPUT gives you unscaled parameters (the final estimates).
The scaling algorithm gives the initial estimates a scaled value of 0.1
(0.1000E+00) for all parameters (see 0th iteration in output) and the range
of the scaled values must cover the region between the upper and lower
bounds (either defined by you or the default bounds). There's more to it
than this, but, this should give you a start.
William J. Bachman, Ph.D.
GloboMax LLC
7250 Parkway Dr., Suite 430
Hanover, MD 21076
Voice (410) 782-2212
FAX (410) 712-0737
bachmanw@globomax.com