Integrator option

2 messages 2 people Latest: Jan 11, 2002

Integrator option

From: Atul Bhattaram Venkatesh Date: January 10, 2002 technical
From:Venkatesh Atul Bhattaram Subject: Integrator option Date: Thursday January 10, 2002 23:30 Hello All. Could somebody share his experience on this! I am trying to develop a pk model for a drug which exhibits complex absorption characteristics using differential equations. I am using a software SCIENTIST in which the user has an option to select the integrator method. I was observing that when I was using Eulers method the final estimates did not make any meaning (some estimates were as high as 10000). But when I used EPISODE STIFF option the estimates were making meaning. Also I observe a goo decrease the sum of squares (least squares estimation). I was wondering why this could be. Also how will the reliability of the estimates might be? Thanks in advance Venkatesh Atul Bhattaram Post-doctoral fellow University of Florida Gainesville-32601 ph: 352-846-3257

Integrator option

From: Vladimir Piotrovskij Date: January 11, 2002 technical
From: Piotrovskij, Vladimir Subject: Integrator option Date: Fri, 11 Jan 2002 08:57:48 +0100 Atul, Euler method is very rough, you'd better not use it for estimation. Best regards, Vladimir ----------------------------------------------------------------Vladimir Piotrovsky, Ph.D.Research Fellow, Advanced PK-PD Modeling & Simulation Global Clinical Pharmacokinetics and Clinical Pharmacology (ext. 5463/151) Johnson & Johnson Pharmaceutical Research & Development Turnhoutseweg 30B-2340 BeerseBelgium Fax: (+3214)605834 Email: vpiotrov@janbe.jnj.com