Definition of equations and variables




I am have used STAN to create some basic models of waste flows and stocks in Bangalore. I would like to know the definition of the equations and variables and how these are calculated. I created a very basic model with 1 input flow, 1 export flow and 1 process with stock. When I pressed the calculation button it said “The math model comprises 5 equations and 8 variables”. What are these 5 equations and 8 variables how are they related to the flows and stocks in my model.

Thank you for answering my basic question.



Hi Megha,

That doesn’t look like any Stan message I’ve seen. Can you tell us what interface you’re using?


I think it might be a different STAN:


Thank you. Yes I was using another STAN


Thank you.