Title: Paul R
I am trying Mats' suggestion for the additive + proportional error
model for some data I am trying to model. (Parent drug and two
sequential metabolites). The model converges successfully when I use
the proportional model (eg., Y1 and Y2. However, when I add the
additive component (Y3), the run stops immediately with the message:
0PROGRAM TERMINATED BY
OBJ
ERROR IN OBJ2 WITH INDIVIDUAL 6
ID=0.60000000E+01
CONDITIONAL CONTRIBUTION OR IT'S DERIVATIVE IS
INFINITE
MESSAGE ISSUED FROM ESTIMATION
STEP
AT INITIAL OBJ. FUNCTION EVALUATION
What is my error? I thought I was preventing a divide by zero with my
FF=1 unless .GT. 0. I look forward to your wisdom.
The $ERROR section of Control stream follows. Thanks in advance. Paul
$ERROR (OBS ONLY)
SW1 = 0
SW2 = 0
SW3 = 0
IF(CMT.EQ.1) SW1 = 1
IF(CMT.EQ.2) SW2 = 1
IF(CMT.EQ.3) SW3 = 1
FF=1
IPRED=LOG(FF)
W1 = THETA(9)
W2 = THETA(10)
W3 = THETA(11)
W4 = THETA(12)
IF (F.GT.0) IPRED=LOG(F)
IF (F.GT.0) FF=F
IRES = DV-IPRED
IWRES1 = IRES/W1
IWRES2 = IRES/W2
IWRES3 = IRES/W3
IWRES = SW1*IWRES1 + SW2*IWRES2 + SW3*IWRES3
Y1 = LOG(FF)+SQRT(W1**2) * EPS(1)
Y2 = LOG(FF)+SQRT(W2**2)*EPS(1)
Y3 = LOG(FF)+SQRT(W3**2+ W4**2/FF**2)*EPS(1)
Y=Y1*SW1 + Y2*SW2 + Y3*SW3
--
Paul R.
Hutson, Pharm.D.
Associate
Professor
UW School
of Pharmacy
777
Highland Avenue
Madison
WI 53705-2222
Tel 608.263.2496
Fax
608.265.5421
Pager
608.265.7000, p7856