NetLogo: Design and Implementation of a Multi-Agent Modeling Environment

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NetLogoDesign and Implementationof a
Multi-Agent Modeling Environment
SwarmFest, May 11, 2004

• Seth Tisue, lead developer
• Uri Wilensky, author and principal investigator
• Center for Connected Learning and Computer-Based
  Modeling
• Northwestern University

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Outline

• Introduction to NetLogo (Wilensky, 1999)whats
  our niche?
• Current and future developmentsgrowing that
  niche

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What is NetLogo?

• A multi-agent programming language
• and integrated modeling environment

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Audience and goal

• Dual audience research and education
• Goal Low threshold, high ceiling

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Why low threshold matters

• Not just for teaching researchers should care
  too
• Rapid development, ease of experimentation and
  prototyping
• Communication, sharing, verification
• Clear box (aka white box)

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Achieving low threshold

• Why a special language?
• Leave out language complexity
• Add language features that are specific to
  agent-based modeling
• Why an integrated environment?
• Reduce complexity of the software development
  process

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NetLogo facts

• Cross-platform (written in Java)
• Free download no restrictions on use
• 147 complete, documented sample models(and 83
  user community models)
• Under development since 1999
• Very active developmentusually 2 or 3 releases
  per year
• Large and active user community

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The NetLogo language

• Logo core
• Adds agents and concurrency
• Successor to StarLisp, CM StarLogo, MacStarLogo,
  and StarLogoT redesigned for both ease and power
• Observer, patches, turtles (and breeds)
• Agentsets
• 2-D spatial relationships(distance, towards,
  etc.)

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More NetLogo features

• Web delivery of models as applets
• BehaviorSpace tool for parameter sweeping
• HubNet, for participatory simulations
• (Wilensky Stroup, 1999)

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Whats new?
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Whats new? Graphics

• Faster, more flexible graphics
• Turtle sizes
• Exact turtle positions
• Label agents with text
• Smooth, flicker-free animation

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Graphics Before
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Graphics Before after
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Graphics
credit Owen Densmore
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Graphics
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Graphics
credit James Steiner
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Graphics
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Whats new? Extensibility

• Extensions API
• Add new commands to language by implementing them
  in Java
• Controlling API
• Script NetLogo from Java, such as for doing
  batch runs

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Whats new? Extensibility

• All-in-one all-or-nothing?
• Transition to a modular architecture
• Bridging the gap between integrated environments
  and libraries

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Whats coming soon?
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Work in progress

• World topologies
• 3-D world, 3-D graphics

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Work in progressProcedural Modeling of Cities

• Now in first year of three-year NSF funded
  project
• Two components
• Land use patterns (including streets roads)
• Building shapes

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creditTom Lechner Ben Watson Pin Ren Martin
Felsen Uri Wilensky Seth Tisue
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Expected spin-offs for NetLogo

• Large, complex, multi-leveled models
• Speed
• Pluggable visualization engines

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Ask me for copies

• Tisue Wilensky, NetLogo A Simple Environment
  for Modeling Complexity ICCS 2004
• Tisue Wilensky, NetLogo Design and
  Implementation of a Multi-Agent Modeling
  Environment SwarmFest 2004
• Lechner, Watson, Felsen, Wilensky, Ren, Tisue,
  Procedural Modeling of Land Use in Cities
  draft

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Try it!

• Explore our Models Library online
• Download application (includes all models)
• http//ccl.northwestern.edu/netlogo/