From: Leonid Gibiansky <*LGibiansky*>

Date: Thu, 04 Jun 2009 17:35:39 -0400

SUM=1+ EXP(THETA(1)+ETA(1)) + EXP(THETA(2)+ETA(2))

F1=EXP(THETA(1)+ETA(1))/SUM

F2=EXP(THETA(2)+ETA(2))/SUM

F3=1/SUM

--------------------------------------

Leonid Gibiansky, Ph.D.

President, QuantPharm LLC

web: www.quantpharm.com

e-mail: LGibiansky at quantpharm.com

tel: (301) 767 5566

Samtani, Mahesh [PRDUS] wrote:

*> Dear NMusers,
*

*> I am using a dual absorption model as follows (The dose is split into 2
*

*> fractions and the splitting fraction, THETA(.), is an estimated
*

*> parameter in the model):
*

*>
*

*> TPH = LOG(THETA(.)/(1-THETA(.)))
*

*> TH = EXP(TPH+ETA(.))/(1+EXP(TPH+ETA(.)))
*

*> F2 = TH
*

*> F1 = 1-TH
*

*>
*

*> However, upon prolonged sampling we can observe a 3rd shallow phase. I
*

*> would like to use a 3-depot absorption process with F1, F2 and
*

*> F3=1-F1-F2. Both F1 and F2 need etas using some type of transformation
*

*> such that neither one of them exceed 1 nor does their sum exceed 1. Can
*

*> some one kindly provide the NONMEM code.
*

*>
*

*> Thanking you in advance,
*

*> Mahesh
*

*> *

Received on Thu Jun 04 2009 - 17:35:39 EDT

Date: Thu, 04 Jun 2009 17:35:39 -0400

SUM=1+ EXP(THETA(1)+ETA(1)) + EXP(THETA(2)+ETA(2))

F1=EXP(THETA(1)+ETA(1))/SUM

F2=EXP(THETA(2)+ETA(2))/SUM

F3=1/SUM

--------------------------------------

Leonid Gibiansky, Ph.D.

President, QuantPharm LLC

web: www.quantpharm.com

e-mail: LGibiansky at quantpharm.com

tel: (301) 767 5566

Samtani, Mahesh [PRDUS] wrote:

Received on Thu Jun 04 2009 - 17:35:39 EDT