Hello, I have a data set with 8 measurements per subject. I would like to fit a nonlinear regression model to each subjects data. The NLR procedure requires data to be in column format where, ostensibly, each row represents one subject. To accommodate the NLR data requirements, I've set my data file up in a 'between-subjects' format, where every 8 rows represents one subject.

Questions: 1. Is it valid to fit NLR models to within-subjects data in this way? 2. If not, are there alternative procedures to fit curves to within-subjects data in SPSS or any other package? The complexity of the regression model prohibits contrast coding in GLM.

Thanks in advance, Michael Healy