Biology: foraging Day 6

1
Biology foragingDay 6

• COLQ 201
• Multiagent modeling
• Harry Howard
• Tulane University

2
Course organization

• http//www.tulane.edu/howard/Multiagent/
• Photos?

3
Photos
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Ants

• Models Library gt Biology gt Ants
• (updated version of the one on the website)

5
Overview

• Set up the model turn plotting on.
• Look at the splotches that are not in the center.
  Notice how far they are from the center splotch.
• Run the model stop it when it stops changing.
• What is the order in which the splotches (food
  sources) are consumed?

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Ant foraging

• How do ants navigate?
• Now let us experiment population 125,
  diffusion 50, evaporation 10.
• Decrease population to 50 run. What is the
  difference?
• Increase population to 200 run. What is the
  difference?
• Test diffusion at 25 75. What is the
  difference?
• Test evaporation at 5 50. What is the
  difference?

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AntSystem

• has several errors

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Programming NetLogo

• Models Library gt Earth Science gt Fire

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Intro to Fire

• Set up
• What do you think the green represents?
• What do you think the red represents?
• What do you think the black represents?
• Run it.
• Experiment
• Lower density to 55. What burns?
• Raise density to 65. What burns?
• Set density to 59. What burns?
• What are the agents?

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Conclusion

• This is an example of a common feature of complex
  systems
• the presence of a non-linear threshold or
  critical parameter.

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How it is programmed

• Switch to the Procedures tab.
• Click on the Procedures pull-down menu. What
  procedures do you see?
• fade-embers
• go
• ignite
• setup
• Find each of these in the code.
• What is the relation of setup and go to the
  interface?

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Procedures

• What is the layout of a procedure?
• What does mean?
• What does ask do?
• What does if do?
• What does set do?

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Turtles patches
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Next time

• Biology migration
• Scatter, Randomly walking