The XH Component
Human / Host Epidemiology and Demography
The XH component handles two dynamical processes and an interface that are inextricably linked:
Human / host epidemiology, the X component
Human / host demography, the H component, including births, deaths, migration, and aging
Principled stratification is an interface that implements a principled method for creating population strata with flows defined among strata that adhere to a set of principles that enforce rigor.
In ramp.xds, a distinction is made between state variables and population strata. In a nutshell, we define a model family for the epidemiology of human malaria (or more generally, the host-specific elements of any host-pathogen interaction) to include a set of state variables as they would be defined for a model with a single population stratum.