Exercise on Agent-Based Modeling

Part 1: Download the NetLogo 5.3 software package (https://ccl.northwestern.edu/netlogo/).

Part 2: Run NetLogo, then open the File scroll down menu, and then open the Model Library, third item from the top.

Part 3: Experiment with the Climate Change Model.

3A) Under Sample Models, expand the Earth Sciences folder, and select the Climate Change model. Read the paragraph description, and then select Open at the bottom right of the Models library interface.

3B) You should see an interface screen with a blank, black output window. At the top center of the interface screen, you should see a bar with [Interface | Info | Code] with Interface selected. Click “setup” near the top left of the interface screen. The blank output screen should show some color (red at bottom for “earth” and black at top for “space”). Now click “go” (right next to “setup”). Observe the animation and changing temperature. After about 90 seconds the temperature will level off at about 26, with some fluctuation. Click the “add CO2” button, and observe the response for about a minute.

3C) At the top [Interface | Info | Code] bar, select [Code] and scan the simulation code, hypothesizing about what the various programming constructs represent in comparison to programming languages that you are familiar with. Then, again on the top bar, select [Info] and carefully read through the ODD.

Part 4 (Deliverables): Create single Word file and enter answers to the following questions. You will upload this Word file.

a) Return to the [Interface] of the Climate Change model and do the activities under “Things to Notice” and “Things to Try” in the ODD. Come to class prepared to discuss. Give your comments on your experiments in your Word document, and optionally add these comments online indexed by {Your Name}.

b) In the Climate Change model, find the code that deflects a ray as the result of encountering a cloud, and change the redirection of the ray to be -1 * the old direction. Copy the revised code snipet into the Word document, with the change clearly indicated in a comment to the code, and with an accompanying screenshot of the interface that clearly shows (e.g., with multiple “watch a ray” traces) that the deflection has changed (you will have to Setup again, with the modified code)

c) The variable “heading” is not declared in the Climate Change model code. Explain how this can be?

d) Find and open the model called “Traffic Grid“, and with default settings, apply Setup and Go. Run the model for one minute and take a screenshot of interface. Include this in the Word document that you submit, along with a paragraph on sustainability-relevant experiments that you could run with this model, and how these experiments might inform road network design.