Dose and concentration unit differences

From: Leonid Gibiansky leonidg@metrumrg.com Subject: [NMusers] Dose and concentration unit differences Date: Thu, 22 Sep 2005 23:33:08 -0400 Hi Toufigh, Is it a linear model ? What exactly is the problem with the model, what type of error NONMEM returns? Have you used any cut-off for the concentration near zero (something like if(F < 0.1) F=0.1 ? Have you tried to increase precision of the computations (SIGDIG=5)? Have you tried to start failing model from the parameter values given by the converged model ? Do you have additive component of the error model? It would be easier to debug the error with the control stream. In general, there should be no difference in solutions, but some minor detail of the model may be not-scalable (or initial values are not-scalable) leading to the differences in computations. Leonid