I am analyzing data from an ambulatory assessment study and I want to specify a latent first-order autoregressive model. Because the time points are randomly selected for each individual, the data has an unbalanced structure: The occasions are not equally spaced and the time lags differ between individuals and between different occasions.
I think that in order to specify such a model the autoregressive parameter has to have the individual time lag in the exponent: beta^time-lag(individual).
Could such a model be specified in OpenMx or is there another way to solve this problem?