# 1 Model Schematic

We provide schematics for different parts of the model outlined here. These are useful because they clarify how different model objects, including data and parameters, are related to one another.

Figure 2.1 illustrates a complete observational model, and in particular details the model for multipliers $$\alpha_t$$. Figure 3.1 presents the basic infection model, and also shows the GLM-style model for reproduction numbers $$R_t$$. Finally Figure 4.1 shows treating latent infections as parameters.

All mathematical notation shown in the figures corresponds to that used in the model description article. Each node is outlined in a color corresponding to the type of object considered. These are interpreted as follows.

• Grey: A user provided object or quantity that is assumed to be known.
• Green: A model parameter that is, generally speaking, directly sampled. Occasionally epidemia will sample a transformation of this parameter for efficiency purposes.
• Red: A transformed parameter. This is a quantity that is a deterministic function of other model parameters.
• Orange: A quantity that is either a parameter or transformed parameter, depending on the context.
• Blue: An observation.