ecosym

Ecosystem simulator inspired by A Primer of Ecology by Nicholas J. Gotelli.

General

ecosym runs basic ecosystem models, e.g. population dynamics under exponential or logistic growth, and plots population over time. Multiple models can be active at once, and you can tweak the model parameters to see how they affect things.

Ecosystem Models

1. Continuous exponential
2. Discrete exponential
3. Environmentally stochastic
4. Demographically stochastic
5. Continuous logistic
6. Continuous logistic with stochastic carrying capacity
7. Continuous logistic with periodic carrying capacity
8. Discrete logistic

How to Run

ecosym runs in web browsers and needs to be hosted by a webserver. To host it, start up a webserver that gives access to the index.html file within the ecosym top-level directory. For example, if you have python (>=3) installed, navigate to the ecosym directory and run

> python -m http.server 8000

This will start a server exposing that directory on port 8000. You can then access the program by pointing your web browser to the URL http://localhost:8000.

Controls

There is a top-level control bar that lets you add new model rows and toggle all rows on or off. Each model row also has a set of controls for its own parameters and display.

Global

• Model Menu - select model type for a new model row
• Add Row button - add a new row with the selected model type
• Activate All checkbox - toggle all rows on or off
• Recalculate button - recalculate population trajectories for stochastic models

Row

• Model Parameters - click the values to edit them. The associated population trajectory will be recalculated and redrawn based on the new values.
• Checkbox - toggles row on or off
• Clone button - add a new row with the same model type and parameters
• Delete button - remove row and associated model

Dependencies

The external dependencies are currently linked from cdnjs.com.

1. jQuery
2. underscore
3. plotly
4. d3 (from d3js.org)
5. Font Awesome