Grid Space Models

Simulation models may include a model of a space that is inhabitated by objects. One particular type of a space model is the two-dimensional discrete Euclidean space, also called grid space, which can be considered as a simplification, or abstraction, of the real world space. In special cases, grid space models may also be one- or three-dimensional.

Grid space models are simulation models that use a grid space for visualizing their discrete state changes. They typically use fixed-increment time progression, which may be combined with next-event time progression.

Due to their simplicity and visual appeal, simulation models based on a grid space have become popular in social science simulation. The wide adoption of the simulation framework NetLogo in social science simulation has contributed to the popularity of grid space models.

Grid space simulation models may still be considered DES models, even if they do not model any explicit events because their time steps may be viewed as implicit time events, similar to other periodic time events, like "every second", "each Monday", "at end of business week". Time events are a special category of events.

Whenever a grid space model does neither model objects nor events, but only grid cell states and grid cell state changes based on the states of neighbor cells, it may be considered a Cellular Automata model.

Examples of Grid Space Models

Schelling Segregation Model
A residential area is populated by residents belonging to some group; periodically, all residents check if they are content with their neighborhood, based on their degree of tolerating neighbors of a different group; if they are not, they move to a location where they are content, or leave the area if they don't find such a location.
Herbivores and Grass
A simulation of grazing behaviors of herbivores and the effects on their population and the ecosystem.