Hello. I'm trying to update a multi-regional Input-Output tables, which means to estimate intermediate trade matrix, you know. And I think about using a RAS variant method, for instance GRAS or KRAS method and so on.

Now, I have information about values of certain cells (intermediate trade value). Do anyone know how can I impose constraints on cell value when RASing matrix? If possible, please tell me the code to execute procedure. Thank you!