Try putting a dummy dose of 1 in the first compartment via your data file records, eg" ID TIME AMT PDK=DV EVID 1 0 1 0 1 for each individual
_____ From: owner-nmus...@globomaxnm.com [mailto:owner-nmus...@globomaxnm.com] On Behalf Of Jing Nie Sent: Thursday, December 03, 2009 9:29 AM To: nmusers@globomaxnm.com Subject: [NMusers] model dynamic data with $DES subroutine Dear NMusers, I have a question I would like your help. The data I have is only the dynamic data since we didn't give dose to the animal. I am trying to capture the nature of disease progression. And the PD decrease with time. I have seen people model only the PD data use $PRED subroutine but they use the explicit equation.But I want to use a differential equation like dA/dt= kin(1-dis)-kout*A while A0=kin/kout. When I ran the control stream, the gradient for most of the parameters are 0. And the only parameter estimation I got is the sigma. The output of Y is 0. I guess it's because I don't have dose to compartment(PDK) but I don't know how should I fix the problem. Any suggestion is appreciated! The control stream I wrote is: $PROB Demo for turn over PD model $INPUT ID TIME AMT PDK=DV EVID $DATA demo.csv IGNORE=# $ESTIM MAXEVAL=3000 NOABORT PRINT=1 METHOD=COND INTERACTION SIG=5 MSFO=save.msf $COV MATRIX=S SLOW $SUBROUTINE ADVAN6 TOL=5 $MODEL COMP=(PDK) $PK KIN=THETA(1)*EXP(ETA(1)) KOUT=THETA(2) DIS=THETA(3)*EXP(ETA(2)) $DES DADT(1)=KIN*(1-DIS)-KOUT*A(1) $ERROR Y = F + ERR(1) ; Fixed effects $THETA 174 FIX ; KIN $THETA 77 FIX ; KOUT $THETA (0,0.28,1) ; AGE_EFFECT_PDK ; Random effects $OMEGA 0 FIX; BSVKIN_PDK $OMEGA 0 FIX; BSVDIS_PDK $SIGMA 0.1 $TABLE ID TIME PDK Y NOPRINT ONEHEADER FILE=DEMO.fit And my data looks like: #ID TIME AMT PDK EVID 101 4 . 1.49 0 102 4 . 1.58 0 61 8 . 0.57 0 62 8 . 2.03 0 63 8 . 1.58 0 64 8 . 1.52 0 109 12 . 0.71 0 110 12 . 1.18 0 21 12 . 1.25 0 -Jing This e-mail and any files transmitted with it, are intended solely for the use of the individual or entity to whom they are addressed.?If you have received this e-mail in error, please reply to this message and let the sender know. _____ Chat with Messenger straight from your Hotmail inbox. Check it out <http://www.microsoft.com/windows/windowslive/hotmail_bl1/hotmail_bl1.aspx?o cid=PID23879::T:WLMTAGL:ON:WL:en-ww:WM_IMHM_4:092009> _____ No viruses found in this incoming message Scanned by iolo AntiVirus 1.5.8.3 http://www.iolo.com <http://www.iolo.com/iav/iavpop3> _______________________________________ No viruses found in this outgoing message Scanned by iolo AntiVirus 1.5.8.3 http://www.iolo.com
