Netlogo Resources
From SCChallenge
Main Software Downloads
- Several versions of NetLogo can be downloaded from the page at this link; however, any new models should be built with v4.0.4 or v4.1 RC1. (In general, NetLogo does a good job of automatically upgrading and opening models created with previous versions; however, sometimes using an older version is necessary, when working with such a model.)
- Notwithstanding the name, NetLogo 3D Preview 5 is a very stable release of NetLogo with a three-dimensional agent space - i.e. each patch is a cube in space, rather than a square on a surface, and turtle agents can move freely in the X, Y, and X directions. This latest preview release has been upgraded to language and feature compatibility with NetLogo v4.x (except for a few primitives whose behavior necessarily changes when moving from two to three dimensions). One very important difference: operations which modify the drawing layer (e.g. turtle drawing with pen-down) tend to be much slower in the 3D version, since the drawing layer there is actually a three-dimensional space, which coexists with the three dimensional agent space, and must support the same rotation, zooming, and sliding operations.
- If you download the v4.1 RC1 version of NetLogo, a separate download of a 3D version isn't needed, since the two versions are being merged into a single install in v4.1.
- Note that both NetLogo v4.x and NetLogo 3D save & open files with the .nlogo extension. If you have both installed, double-clicking a file with that extension generally opens the most recently installed version of NetLogo – which may not be what you intended to do. Thus, when using both versions, it is often easiest simply to launch the desired version, and open models using the File/Open menu command.
- The architecture of NetLogo supports the construction and installation of extensions developed in Java. In fact, new features are often first implemented as extensions, before incorporating them into the main toolset. Currently, there are a number of standard extensions installed along with NetLogo itself; the page linked to here includes a few other extensions that many have found useful (particularly the GIS extension).
Documentation
These are the same user manuals that are installed automatically with the software.
Tutorials & Samples
Three tutorials are included with the user manuals installed along with the software (also available online, see above links). In addition to these, we've created a number of tutorials and examples in the Supercomputing Challenge, GUTS, and SFI Summer Internship-Mentorship programs.
- VAnts is one of the simplest models to build, but its behavior can surprise even those who have experience in agent-based modeling and complex systems.
- Heatbugs is a classic model showing emergent behavior; almost every agent-based modeling & simulation tool includes a version of it. This is a tutorial for building a conceptually identical but simpler version of the Heatbugs model found in the NetLogo models library.
- The cyclical dominance feature found in the familiar game of rock-paper-scissors has interesting parallels in real-world biological systems. This tutorial presents one of those parallels (an E. coli ecosystem), and uses that as a point of reference in building a NetLogo rock-paper-scissors model.
- In teaching and learning agent-based modeling & programming, we often find it helpful to use "mystery models" and "mystery patterns". In the former, students watch the behavior of an unknown model, then form and test hypotheses about the rules guiding the individual agents; in the latter, students are led through the process of building a model with simple agent behaviors, but without being being told what to expect when the model is complete. This tutorial is an example of the mystery pattern approach, where a very simple behavior (randomly selecting one corner of a triangle, moving half-way toward the selected corner, then stopping and marking the current patch) results in a surprisingly rich pattern, when repeated many times.
- This is a NetLogo 3D implementation of the N-body problem, simulating the orbits of the gas giants of our solar system (Jupiter, Saturn, Uranus, Neptune) around the Sun. It includes an optional feature, in which a "rogue giant planet" can be dropped into the Sun's gravitational well, and the user can watch the effect on the orbits of the other planets.
- This model has the capability to take periodic "snapshots" of the system; using Quicktime, you can stitch these .png images together to build an animation that can be replayed without having to re-run the model. Take care when using this feature: the directory where the model is located can quickly balloon with thousands of these images. Also, there is an option to have the planets trace out their orbital paths; however, as noted above, this type of operation slows down NetLogo 3D considerably.
