which variable is a independent variable in r? what is the residual variance of the variable x nlme in r when a drug is injected what is the residual how to model for time change how to model time on drug doses when do we model the residuals what is residual variance for drug dose change what is the r residual for time nlme model for residuals which variable is the dependent variable for a model of drug effect what is residual variance of the sample model how to find residual variance what is residual nlme nlme model for residuals of drugs what variable is a controlled rat what is the relationship between dose and time what is the dependent variable of a mixed model? what is the residual variance structure how do you do a mixed model of time and doses in rats what is residual in r