It seems that OpenMx does not allow specifying a model without a dataset (see error message (1)). Sure, we will eventually need a dataset to run the model but at design time, I might not have a dataset yet. Only later in the program I might decide to load different datasets and associate them with the same model while at first the dataset reference could be NULL.
Shouldn't OpenMx allow NULL or some kind of empty dataset and test only within run() whether there is a valid dataset available?
(1) Error: The RAM objective does not have a dataset associated with it in model XXX