Error model

From:"Rajanikanth Madabushi" Subject: [NMusers] Error model Date:Mon, 21 Apr 2003 20:13:23 -0400 Dear NONMEM users I have a query: In NONMEM users guide VIII page no. 312 for the exogenous supplementation example, the error model used has been mentioned as combined additive and ccv error model and is as follows: $ERROR FP=THETA(7)+F ; adds endogenous component W=(1+THETA(8)*THETA(8)*FP*FP)**.5 Y=F+W*ERR(1) My query to the group is: 1) Is this error model same as error model using two random variables like: Y = F*(1+ERR(1)) + ERR(2) 2) What are the specific advantages and disadvantages of either of the error models? Thanking in advance Raj Rajanikanth Madabushi Post Doc Assoc Dept. of Pharmaceutics University of Florida Gainesville _______________________________________________________