Dear R Gang, I'm interested in using R and the nls package for fitting kinetic models. I'm having some difficulty getting a model specified for nls though. The math for the model that I want to fit is
dg(t)/dt = K1 f(t) - k2 g(t) where g(t) and f(t) are measured data at a sequence of times t. K1 and k2 are the parameters of the model. If I solve this, the solution is g(t) = K1 \int_0^t f(t') \exp(-k2(t-t')) dt' and I'm not sure how to write a formula in R that I can pass to nls that will handle both the implicit loop over the data values of t and the interpolation and numeric integration over t'. Can anyone help me to get this properly coded for R? Mike -- Michael A. Miller [EMAIL PROTECTED] Imaging Sciences, Department of Radiology, IU School of Medicine ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help