[R] curve peeling

From: Greg Tarpinian <sasprog474474_at_yahoo.com>
Date: Sat 27 May 2006 - 04:45:53 EST


R2.3.0, WinXP.

I am trying to fit the model

   Y(t) = C1*exp(-exp(a)*t) + C2*exp(-exp(b)*t) - (C1+C2)*exp(-exp(c)*t)

to some pharmacokinetic data. The data derives from a single oral dose of a drug. Does anyone know how to use peeling and/or other methods to obtain good starting estimates of the parameters in the triexponential?

The book "Mixed Effects Models in S and SPLUS" describes self-starting models for the biexponential and first-order one-compartment PK models, but not for the triexponential.

Much thanks in advance,

   Greg



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