What's New?

Feedback from users is very valuable to us in designing and improving NetLogo. We'd like to hear from you. Please send comments, suggestions, and questions to feedback@ccl.northwestern.edu, and bug reports to bugs@ccl.northwestern.edu.

Version 4.1.3 (April 2011)

• improvements:
  • the GIS extension now works in applets
  • new Code Example: Label Position Example
• fixes:
  • fixed bug in diffuse primitive causing it to fail in vertical cylinder worlds
  • fixed bugs where aborting a BehaviorSpace experiment could cause an error or memory leak
  • fixed bug where a turtle forever button could fail if multiple buttons were pressed quickly
  • fixed bug in scale-color primitive where rounding could cause an out-of-range color to be reported
  • fixed matrix extension bug where matrix creation primitives didn't sanity check their inputs
  • fixed GoGo extension bug where failed initialization of GoGo led to subsequent errors
  • fixed intermittent plotting bug
  • for Windows users, bundle Java 6 Update 24
• API changes:
  • controlling API now allows a new model to be opened in an existing InterfaceComponent
  • controlling API now supports attaching listeners to receive notifications of user actions

Version 4.1.2 (December 2010)

• fixes:
  • Windows installer now adds NetLogo 3D to the Start menu
  • fixed BehaviorSpace issue where compile errors in experiment setups caused exceptions
  • fixed regression in 4.1.1 where extension-defined data types could cause errors in the GUI (e.g. in agent monitors)
  • fixed extensions issues where NetLogo could get confused about what extensions are active
  • fixed NetLogo 3D so the stamp command works for links
  • fixed bug where pow primitive could give NaN result
  • fixed bug where the F1 key didn't work on several primitives
  • fixed bitmap extension so importing works in applets
  • fixed bugs where typing certain combinations of keys or characters in the Command Center caused exceptions
  • fixed agentset building primitives to give correct error messages on invalid inputs
  • fixed bug where logging of global variables didn't work under Java Web Start
  • fixed matrix extension issue where matrix:dimensions was incorrectly typed
  • HubNet clients now limit the rate at which they send messages, to conserve bandwidth
  • for Windows users, bundle Java 6 Update 22
  • GIS extension now includes license information
• API changes:
  • extensions API: deprecated runCommand and runReporter methods
  • controlling API: added possibleViewUpdate() and tickCounterChanged() methods to NetLogoListener
  • logging: changes to the tick counter are now logged (exactly as if ticks was a global variable)

Version 4.1.1 (August 2010)

• additions:
  • new matrix extension for matrix manipulation
  • new behaviorspace-run-number reporter
  • new biology model: Flocking Vee Formations
  • new Donate item on Help menu
• fixes:
  • fixed models: Dining Philosophers, Sandpile 3D, Shepherds, Connected Chemistry 8 Gas Particle Sandbox
  • on Windows, bundle Java 6 Update 21
  • fixed embedding API bug where two models could not be embedded in the same window
  • fixed bug where in worlds with certain unusual combinations of settings, passing specific unusual inputs (involving patch boundaries) to primitives including patch-at and patch-at-heading-and-distance could cause a Java exception
  • fixed bug causing some models with plots to intermittently produce spurious error messages
  • fixed (we hope) intermittent bug where editing code in the procedures tab or command center could cause spurious ArrayIndexOutOfBoundsException errors
  • fixed bug in 2D view where partially transparent turtles were sometimes rendered incorrectly in some sizes
  • fixed bug where saved applets that used extensions didn't load additional jars used by the extension
  • fixed bug where closing a browser window containing applet could cause a spurious error dialog to appear
  • fixed bug where the link primitive could fail when given a non-existent turtle number
  • fixed bug where the mini views in agent inspectors could have incorrect appearance with very small patch grids
  • fixed bug where the context menu on the view in applets contained some non-working items
  • fixed bug where movie primitives didn't fail gracefully when used in parallel BehaviorSpace runs
  • fixed bug where changing a plot pen's mode on the fly didn't refresh the plot
  • fixed bug causing models using links not to work in the NetLogo Logging application
  • fixed bug where new-seed primitive could theoretically return duplicate seeds in a parallel BehaviorSpace experiment
  • fixed sound extension bug where the wrong instrument sometimes played
  • fixed bug where using follow could cause turtle labels not to be drawn
  • fixed bug where the remove primitive didn't fail gracefully if given incorrect input
  • fixed HubNet bug where the drawing layer wasn't always mirrored to clients
  • fixed GIS extension bug where clipping of coordinates to user's GIS envelope was causing errors saving link datasets
  • fixed bitmap extension so it works in applets
  • on Mac OS X, always force use of the Quartz renderer not the Sun renderer

Version 4.1 (December 2009)

• system:
  • NetLogo 3D is no longer a separate download (but is still a separate application)
  • Java 5 or higher is now required
  • NetLogo and its applets no longer support Mac OS X 10.2, Mac OS X 10.3, Windows 98, or Windows ME
  • the Windows installer and launcher are new and should be compatible with more systems
  • on Windows, we now bundle Java 6 (instead of Java 5)
  • on 64-bit Linux, 3D now works
  • on Mac OS X, the application now works with 64-bit Java (though by default it still runs in 32-bit)
  • BehaviorSpace is now free and open source software (under the LGPL)
• features:
  • BehaviorSpace is now multi-threaded so runs happen in parallel
  • Controlling API now supports embedding of models in a surrounding application
  • automatic indenter for code in the Procedures tab
  • Models Library dialog now offers searching
  • links, turtles, and the drawing may now be partially transparent (RGB colors only, 2D view only)
  • agent monitors now include a mini-view centered on the agent
  • extensions that use additional jars now work in applets
  • the sound extension is now supported in applets
  • new resize-world and set-patch-size commands allow changing the dimensions of the patch grid
  • applet web pages now include color-coded Procedures tab contents
  • new bitmap and QTJ (QuickTime for Java) extensions allow importing image and video data
  • the GoGo extension now supports "burst mode"
• language changes:
  • set [variable] of ... is no longer allowed; use ask ... [ set variable ... ] instead
  • the with-min and with-max primitives now have the same precedence as with
• user interface changes:
  • new menu item on Tools menu closes all agent monitors
  • new NetLogo Users Group item on Help menu
  • the snap-to-grid setting in the Interface tab is now saved with the model
  • turning off turtle and link shapes is no longer supported
  • the 3D and 2D views may now both be active at the same time (for 2D models)
  • improved fonts on Windows
  • improved look-and-feel on Linux
• bug fixes:
  • a single web page may now contain multiple NetLogo applets
  • the __includes keyword now works in applets
  • the profiler extension is now much faster
  • fixed system dynamics modeler bug where incorrectly parenthesized code was generated for some expressions
  • fixed system dynamics modeler bug where some models did not work correctly when run in headless mode
  • the array and table extensions are now fully compatible with exporting and importing worlds
  • some link primitives are now faster on dense networks
  • fixed bug where using the precision primitive with negative precisions could give non-integer results
  • improved error detection on extremely large integers
  • fixed bug in forward primitive in non-toroidal worlds
  • fixed bug where link agentsets sometimes behaved incorrectly when links died
  • fixed bug in world importing where links stored in agent variables weren't imported correctly
  • fixed bug in run and runresult primitives where running the same string from different procedures could cause a Java exception
  • fixed bug where in some situations zero wasn't always considered equal to itself (e.g. in the remove-duplicates primitive)
  • fixed bug affecting 3D models where layout-circle and tie could cause a Java exception
  • fixed bug where the NetLogo window tended to jump between monitors on multiple-monitor systems
  • fixed bug in text editing where a single edit sometimes required multiple Undo actions to undo
  • fixed bug where export-interface didn't always work properly on Windows and Linux
  • fixed bug where extensions that use native libraries (e.g. GoGo) could not be reloaded
• HubNet:
  • the HubNet client is now available as a Java applet which can be embedded in web pages, so users can participate in an activity without installing NetLogo
  • new feature: support for individualized client views, via:
    • client overrides (hubnet-send-override)
    • client perspectives (hubnet-send-watch, hubnet-send-follow)
  • new commands hubnet-send-message, hubnet-broadcast-message, hubnet-send-clear-output, and hubnet-broadcast-clear-output
  • new event type: mouse up events are now sent
  • fixed longstanding performance issue that was causing activities to use excessive amounts of bandwidth (especially activities with many monitors)
  • assorted bugfixes to view mirroring and plot mirroring
  • removed obsolete hubnet-send-view command
  • new activity: Memory HubNet
  • improved activity: Sampler (overhauled, now verified)
  • improved Code Example: Template
  • new Code Examples: Client Perspective Example, Client Overrides Example
• models:
  • NIELS suite of electromagnetism models expanded and revamped, and is now found in Curricular Models
  • new biology model: Sunflower Emergent
  • new social science models: Sugarscape 1, 2 and 3
  • new computer science models: Simulated Annealing, PageRank
  • new game: Projectile Attack
  • new code examples: Move Towards Target Example, Transparency Example
  • new evolution model: Bug Hunt Drift (in Curricular Models)
  • new ProbLab probability models (in Curricular Models): Histo Blocks, 4 Blocks, 4 Block Stalagmites, 4 Block Two Stalagmites, Sampler Solo
  • improved evolution models: Bug Hunt Camouflage (includes RGB genes, measure of genetic variance), Bird Breeder (conceptual fix), Bug Hunt Speeds (overhaul)
  • improved Biology models: Daisyworld (bugfix), Flocking (bugfix), Wolf Sheep Predation (bugfix)
  • improved Earth Science model: Percolation (colors, clarified info)
  • improved Computer Science models: Artificial Neural Net (code overhaul), Dining Philosophers (simplified)
  • improved chemistry models: Simple Kinetics 1 & 2 (bugfix), Connected Chemistry 3 Circular Particles (bugfix)
  • improved code examples: Moore and Von Neumann Example (simpler code)
• BehaviorSpace fixes:
  • stop conditions now run without affecting the main random generator
  • reduced memory usage when not generating spreadsheet output
  • aborting an experiment no longer discards accumulated spreadsheet output
  • the options for running from the command line have changed (table output is no longer generated by default)
  • improved error reporting when running headless
• extensions API:
  • the interfaces in org.nlogo.api involving agents and agentsets now have many additional methods
  • extensions that define custom data types can now add support for import and export of those types
  • extension primitives may now take a variable number of inputs
  • an example extension written in Scala is now included

Version 4.0.5 (December 2009)

• bugfixes

Version 4.0.4 (November 2008)

• GIS extension for handling geographic data
• applets now include "powered by NetLogo" notice, linked to NetLogo site
• bugfixes

Version 4.0 (September 2007)

• features:
  • most models now run somewhat faster:
    • while results vary from model to model, typical speedup is around 1.5x
    • the speedup comes from an improved compiler that now partially compiles NetLogo code into Java byte code
  • links are now their own type of agent, alongside turtles and patches; this is useful for network models, geometry models, and much else
  • new Link Shapes Editor lets you control the appearance of links
  • logging allows researchers to record students' actions for later analysis
  • built in tick counter for keeping track of model time (see language changes, below)
  • new view update system:
    • there are now two view update modes, tick-based and continuous
    • continuous is the default when you start up NetLogo; tick-based is the default for most models in the Models Library; continuous update mode is useful for non-tick based models like Termites, but may also be useful during debugging
    • tick-based updates are faster for most models and avoid displaying intermediate state
    • buttons no longer have a "force view update" checkbox; most models should use tick and/or display instead
  • improved speed slider:
    • you can now use the slider to "fast forward" a model (by updating the view less often)
    • in tick-based update mode, going slower pauses between ticks rather than showing intermediate states
    • in continuous update mode, going slower shows intermediate states; you can even go so slow you can watch agents move one at a time
  • new input boxes in Interface tab permit entering text, numbers, colors, or NetLogo code as model parameters
  • arrays and hash tables are now supported via extensions (see Arrays & Tables section of User Manual)
  • new profiler extension lets you measure the running times of your procedures
  • new experimental __includes keyword allows splitting model code into multiple source files
  • color variables can now contain either a NetLogo color or an RGB color (as a list of three numbers)
  • programmable slider bounds (you can now use any NetLogo reporter as the min, max, or increment of a slider)
  • exporting the world now includes all plot data, and when you import a world the contents of plots are restored
  • the sound extension can now play audio files in addition to MIDI sounds
  • notes, monitors and output areas now have editable font size
  • the color of text in notes is now editable, and a note's background may now optionally be transparent
  • "Snap to Grid" in Interface tab
  • added menu items (and F1 keyboard shortcut) for quickly accessing NetLogo Dictionary
  • sliders may now be vertical or horizontal
  • model files with unsaved changes are auto-saved to a temporary files directory, in case of freezes/crashes
  • HubNet clients are much easier to edit now (the client is no longer a separate model)
  • Mathematica-NetLogo link provides a real-time link between Mathematica and NetLogo, for controlling model runs and visualizing and analyzing results after the fact or in real time
  • the run and runresult primitives are now drastically faster when called repeatedly on the same string
  • internally, lists are now represented as linked lists, not arrays
  • plotting is now supported when running headless
• language changes:
  • the ask command now always runs "without interruption"; if you need the old-style concurrent behavior, use ask-concurrent
  • turtle who numbers are now never reused until clear-turtles or clear-all
  • all numbers are now represented internally using double precision floating point
  • the + operator only adds numbers now; it doesn't work on strings or lists anymore; models must be changed by hand to use word instead for strings and sentence instead for numbers
  • create-turtles now makes turtles with random headings and colors; to get evenly spaced turtles with sequential colors and id numbers use create-ordered-turtles (cro for short)
  • extension primitives must now (by default) be referred to using the extension name, e.g. sound:drums instead of just drums
  • new uphill, uphill4, downhill, and downhill4 commands for doing hill-climbing replace old reporters with same names
  • new tick counter primitives: tick, ticks, tick-advance, reset-ticks
  • new primitive of replaces VARIABLE-of, value-from, values-from
  • other new primitives: all?, other, move-to, turtle-set, patch-set, link-set, no-turtles, no-patches, no-links, tie, untie, min-n-of, max-n-of, with-local-randomness, file-flush, base-colors, plot-pen-exists?, import-pcolors-rgb, netlogo-applet?

Version 3.1 (April 2006)

• topologies (wrapping at world edges now optional)
• automatically randomized ordering of agentsets
• experimental link primitives

Version 3.0 (September 2005)

• 3D view (for 2D models)
• System Dynamics Modeler
• follow, ride and watch commands for tracking particular agents
• "drawing layer" for marks left by turtles
• GoGo extension for robotics and devices
• buttons take turns now (instead of interleaving their code with each other)

Version 2.1 (December 2004)

• "headless" mode for command line operation
• "action keys" let buttons be triggered by keypresses
• makes QuickTime movies of models
• add "output area" to models
• new primitives including let and carefully

Version 2.0.2 (August 2004)

• extensions API for writing commands and reporters in Java
• controlling API for controlling NetLogo from external Java code
• sound extension for making sounds and music

Version 2.0 (December 2003)

• full support for Mac OS X and Linux
• Windows 95, MacOS 8/9 no longer supported
• fast, flicker-free, non-grid-based graphics
• strict math mode for identical results cross-platform

Version 1.3 (June 2003)

• view control strip
• choosers
• new primitives including run, runresult, map, foreach, filter, reduce
• some primitives accept a variable number of inputs

Version 1.2 (March 2003)

• computer HubNet

Version 1.1 (July 2002)

• "Save as Applet"
• printer support
• Procedures menu
• scrollable Interface tab

Version 1.0 (April 2002)

• initial release (after a series of betas)