[NMusers] Combined residual model and IWRES.

2008-02-14 Thread Paul Westwood
Dear All, I'm working on a one-compartment iv model. I have used a model for the IWRES from a discussion from May 2001 (thanks to Mats Karlsson, Niclas Jonsson and Nick Holford), where you use thetas to obtain the sigmas when using a combined residual model: IPRED=F IRES=DV-IPRED

Re: [NMusers] Combined residual model and IWRES.

2008-02-14 Thread Leonid Gibiansky
sorry for the typo in my first e-mail, I was talking about SIGMAs, not OMEGAs, Below is the corrected version Leonid Paul, In thetas, SE% refers to SE% of SD while in SIGMAs it refers to variances (SD^2). To make them identical, use

Re: [NMusers] Combined residual model and IWRES.

2008-02-14 Thread varun goel
Dear Paul, You can use the delta method to compute the variance and expected value of a transformation, which is square in your case. given y=theta^2 E(y)=theta^2 Var(y)=Var(theta)+(2*theta)^2 ; the later portion is square of the first derivative of y with respect of theta. In