SPEED Lab Android Mobile Applications

Mobile Android Application: Spatial Population Ecological and Epidemiological Dynamics Simulator, Version 1.0

This app is being deployed on the Google Play store for Android devices (phones and tablets. It allows users to interactively explore the dynamics of spatial simulation models.

Below is more information about the models included in Version 1.0 of the application. Additional models are planned for future versions of the software.

Life: Conway's Game of Life
Vants: Langton's virtual ants
Majority: Majority rule or voter model cellular automaton
DLA: Diffusion-limited aggregation particle model
Cyclic: Generalized "rock paper scissors" in the lattice
SIRS: Spatial epidemiological model.
Dispersal 2: Population model with local dispersal at distance 1 or 2, and long-distance dispersal.
Fragmented Habitat: Population on a landscape with habitat loss and fragmentation
Competitive Species: Two species competing on a landscape with habitat loss and fragmentation
Block Disturbance: Using large-scale disturbance events to control an unwanted species
Vaccinated communities: Epidemiological model with varying vaccination levels among different communities.

User interface

Here is some basic information about the user interface for the application. On tablets, the Lattice panel will almost always be visible, along with one of the other panels. On phones or other small devices, only one panel will be visible at a time. Tap the left/right arrows at the edges of the display to cycle through which panel is visible.

Lattice panel

You can use pinch-to-zoom with the lattice to magnify it, and drag the view around if you are zoomed in.
Some models support drawing in the lattice. Tap and hold on the lattice screen, to draw in the lattice. The Drawing panel lets you choose which state/color you are drawing, and the brush size.
Tap "Continue" to begin the simulation; the "Continue" button then becomes a "Pause" button to stop the simulation. Tap "Single Step" to do just one step of computations and then pause again.
Tap "Restart" to reinitialize the model and start a fresh simulation.
Tap "Reset Defaults" to reset all parameters to their default values and reinitialize the model.
Drag the "Slow/Fast" slider near the image to adjust the speed of the simulation.
Some models involve populations with heterogeneous habitat, or vaccinations. For those models, when you begin running the simulation, the habitat will first begin changing until the level of clustering has reached the desired level. The population will then be initialized on that landscape and the full model will run.

Parameters panel

This panel displays parameters specific to the current model. Some of the parameters take effect right away (such as birth rates, infection rates, etc.), while others take effect when the model is reset (such as initial infections, etc.).

On tablets, you can tap the triangle in the gray band to expand the parameters panel to full-screen, hiding the view of the lattice. Tap the triangle again to go back to the split view with lattice and parameters.

State variables panel

The state variables panel displays the current values for the various things simulated in the model, such as the population density, proportion of sites infected, or proportions of sites that have the different values in the model.

Plot panel

The plot panel displays a graph of the various state variables over time. You can pinch to zoom, and pan around within the plot just as you can the lattice.

Model description panel

This panel displays a description of the model, and a color-key showing what the various colors in the lattice represent.

Drawing panel

Here you can control which state will be drawn when you tap-and-hold in the Lattice view, as well as the brush size for drawing.

The application menu (which may be accessed from your device's menu button, or perhaps via an on-screen icon; this icon appears as just three dots on some devices) lets you select a different model, either from a text list or by browsing thumbnails of the models. Here you can also access information about the application, including this important acknowledgement of funding: This app is based on work supported by the National Science Foundation under Grant Nos. DMS-0718786 and DMS-0746603 to David Hiebeler.

Known issues/problems

None yet, but we are new to Android development, and the application behaves quite differently among the few devices we tested on. There are so many different devices out there, please let us know if there are issues on yours.