9models/3D/Code Examples/Airplane Landing Example 3D.nlogo@This model is an animation of an airplane landing at an airport.7models/3D/Code Examples/Bouncing Balls Example 3D.nlogoHThis is an example that displays many of the capabilities of NetLogo 3D.6models/3D/Code Examples/Hill Climbing Example 3D.nlogoThis example shows make a terrain in 3D and move turtles across the terrain. This is much like the Hill Climbing Example in 2D. However, the elevation variation in the terrain is visible in the 3D space.6models/3D/Code Examples/Neighborhoods Example 3D.nlogoThis is a 3D version of the 2D model Neighborhoods Example This code example shows how to use the basic 2D and 3D neighborhood primitives in a 3D world. These include neighbors, neighbors6, in-radius, and at-points:0models/3D/Code Examples/Network Example 3D.nlogoThis is a 3D version of the 2D model Network Example. The only significant difference from the 2D code is that we spread the nodes around the world in 3D space./models/3D/Code Examples/Shapes Example 3D.nlogoOThis code example shows all of the 3D shapes currently available in NetLogo 3D.7models/3D/Code Examples/Spherical Path Example 3D.nlogoThis shows how to make turtles move along a perfect sphere. The first procedure moves turtles based a user-defined distance to be travelled; the second moves then based on a user-defined degree measure.4models/3D/Code Examples/Three Loops Example 3D.nlogoThis model shows three turtles moving around in 3D NetLogo. The gray turtle is changing only pitch and moving forward, the red turtle is changing only roll, and the orange turtle is changing pitch, roll, and heading as it is using right3d./models/3D/Code Examples/Trails Example 3D.nlogoZThis code example shows how to use turtles to draw lines that trace a turtle's trajectory.Cmodels/3D/Code Examples/Turtle and Observer Motion Example 3D.nlogo=This model lets you explore turtle orientation in a 3D world.5models/3D/Code Examples/Turtle Dance Example 3D.nlogoThis is a simple Code Example to help new users understand how turtles move in 3D space. On each tick each turtle will move forward, turn left and pitch up.;models/3D/Code Examples/Turtle Perspective Example 3D.nlogoIThis is an example that demonstrates changing perspectives in NetLogo 3D.Imodels/3D/Code Examples/Uniform Distribution on a Sphere Example 3D.nlogoWThis code example demonstrates the correct way to uniformly distribute turtles on the surface of a sphere. Note that simply setting the heading and pitch to random numbers between 0 and 360 results in a non-uniform distribution with clustering at the poles in the z direction. The solution in SETUP-UNIFORM is based on information found here:$models/3D/Sample Models/DLA 3D.nlogomThis is a 3D version of the 2D model DLA. This model demonstrates diffusion-limited aggregation, in which randomly moving (diffusing) particles stick together (aggregate) to form beautiful treelike branching fractal structures. There are many patterns found in nature that resemble the patterns produced by this model: crystals, coral, fungi, lightning, and so on.*models/3D/Sample Models/Fireworks 3D.nlogoThis program models the action of fireworks. Rockets begin at the bottom of the world, shoot upwards into the sky and then explode, emitting showers of falling sparks.3models/3D/Sample Models/Flocking 3D Alternate.nlogoThis is a vector-based 3D flocking model, based on Jon Klein's implementation of Craig Reynolds' Boids algorithm. Each bird is influenced by a series of urges. By assigning different weights to each urge, the birds exhibit different flocking behaviors.)models/3D/Sample Models/Flocking 3D.nlogotThis is a 3D version of the Flocking model in the NetLogo Models Library. This model is an attempt to mimic the flocking of birds. (The resulting motion also resembles schools of fish.) The flocks that appear in this model are not created or led in any way by special leader birds. Rather, each bird is following exactly the same set of rules, from which flocks emerge.)models/3D/Sample Models/Follower 3D.nlogoThis is a 3D version of the Follower model found in the Art section of the Sample Models. In Follower, turtles attempt to "connect" with other turtles, forming long chains according to a small set of simple rules.7models/3D/Sample Models/GasLab/GasLab Free Gas 3D.nlogo This model is a 3D version of the 2D model Gas Lab Free Gas; it is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.?models/3D/Sample Models/GasLab/GasLab Single Collision 3D.nlogoThis model is a 3D version of the 2D model GasLab Single Collision; it is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.6models/3D/Sample Models/GasLab/GasLab Two Gas 3D.nlogo This model is a 2D version of the 3D model Gas Lab Two Gas; it is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.%models/3D/Sample Models/Life 3D.nlogoThis program is an example of a three-dimensional cellular automaton, it is a 3D version of the Life model. A cellular automaton is a computational machine that performs actions based on certain rules. It can be thought of as a world which is divided into cubic cells. Each cell can be either "alive" or "dead." This is called the "state" of the cell. According to specified rules, each cell will be alive or dead at the next time step.+models/3D/Sample Models/Mousetraps 3D.nlogoThis is a 3D version of the Mousetraps model. Imagine a gymnasium full of mousetraps. On each mousetrap is a ping pong ball. Now throw a single ping pong ball into the middle of the room. The ball lands on a trap, the trap triggers, and a second ball flies into the air. The first ball also bounces into the air again, so now there are two balls in the air. Each of those two balls triggers another trap, so there's four balls in the air. And so on...,models/3D/Sample Models/Percolation 3D.nlogo*This model is a 3D version of the 2D model Percolation. It shows how an oil spill can percolate down through permeable soil. It was inspired by a similar model meant to be done by hand on graph paper (see "Forest Fires, Oil Spills, and Fractal Geometry", Mathematics Teacher, Nov. 1998, p. 684-5).*models/3D/Sample Models/Raindrops 3D.nlogoThis is a 3D version of the 2D model Raindrops, it simulates raindrops falling on the surface of a pond and the waves they produce.%models/3D/Sample Models/Rope 3D.nlogoThis project simulates a wave moving along a rope. One end of the rope is green, and the other is blue. The ends of the rope may be driven in sinusoidal motion (along the y and z axes), causing wave patterns to travel along the rope. This creates a wave that travels along the rope.%models/3D/Sample Models/Sand 3D.nlogozThis is a model of how sand particles interact with each other. The sand particles move according to the following rules:)models/3D/Sample Models/Sandpile 3D.nlogoThis model illustrates a phenomenon known as self-organized criticality. The world is filled with sand organized in columns. Falling sand stacks on top of the sand that is already there. Eventually a column will fall over because it gets too high, and the sand will spill into the surrounding area. This is called a cascade. When a falling column causes other columns to fall, the series of cascades is called an avalanche. The size of an avalanche is the number of cascades that occur from one grain of sand falling.2models/3D/Sample Models/Sierpinski Simple 3D.nlogoThis is a 3D version of the Sierpinski Simple model in the NetLogo Models Library. The fractal that this model produces was discovered by the great Polish mathematician Waclaw Sierpinski in 1916. Sierpinski was a professor at Lvov and Warsaw. He was one of the most influential mathematicians of his time in Poland and had a worldwide reputation. In fact, one of the moon's craters is named after him.*models/3D/Sample Models/Sunflower 3D.nlogo&This is a 3D version of the Sunflower model in the NetLogo Models Library. The interlocking spirals found in the seeds, petals and even branches of many plants occur naturally through the growth of the flower. This model attempts to demonstrate the growth of these naturally occurring spirals.0models/3D/Sample Models/Surface Walking 3D.nlogoThis model is a 3D version of a surface-walking algorithm used in "Surface Walk 2D". Turtles approximate a user-defined surface using a simple algorithm that considers the turtle's current position relative to neighboring surface patches.)models/3D/Sample Models/Termites 3D.nlogoThis is a 3D version of the Termites model. This project is inspired by the behavior of termites gathering wood chips into piles. The termites follow a set of simple rules. Each termite starts wandering randomly. If it bumps into a wood chip, it picks the chip up, and continues to wander randomly. When it bumps into another wood chip, it finds a nearby empty space and puts its wood chip down. With these simple rules, the wood chips eventually end up in a single pile.,models/3D/Sample Models/Tree Simple 3D.nlogoThis is a 3D version of the 2D model Tree Simple. This model draws special types of pictures called fractals. A fractal is a shape that is self-similar - that is, it looks the same no matter how closely you zoom in or out. For instance, a tree can be thought of as a fractal since if you look at the tree as a whole, you see a stick, that is to say the trunk, with branches coming out of it. Then if you look at a smaller portion of it, say a branch, you see a similar thing, namely, a stick with branches coming out of it.-models/3D/Sample Models/Wave Machine 3D.nlogoThis is a 3D version of the 2D model Wave Machine. This model simulates wave motion in a membrane. The four edges of the membrane are fixed to a frame. A green rectangular area represents a driver plate that moves up and down, exhibiting sinusoidal motion.,models/Code Examples/3D Shapes Example.nlogo;This code example shows the 3D shapes available in NetLogo./models/Code Examples/Ask Ordering Example.nlogoAgentsets in NetLogo are always in random order. This code example demonstrates that visually. It also shows how to make the turtles execute in a particular order if you want.1models/Code Examples/Ask-Concurrent Example.nlogoHThis example demonstrates the difference between ASK and ASK-CONCURRENT.)models/Code Examples/Bounce Example.nlogo9This demo shows how to make turtles bounce off the walls..models/Code Examples/Box Drawing Example.nlogo\This example sets up a box that can be placed anywhere in the world. It is one patch thick.3models/Code Examples/Breed Procedures Example.nlogomThis shows how to use the RUN command to give different breeds different definitions of the "same" procedure.4models/Code Examples/Breeds and Shapes Example.nlogoQThis code example shows how to create and control groups of turtles, i.e. breeds.2models/Code Examples/Case Conversion Example.nlogoNetLogo doesn't have primitives for converting upper to lower case, or vice versa. This example includes procedures that accomplish these tasks.0models/Code Examples/Circular Path Example.nlogoThis shows how to make turtles move along a perfect circle. The first procedure moves turtles based a user-defined distance to be travelled; the second moves then based on a user-defined degree measure..models/Code Examples/Color Chart Example.nlogoKThis model was used to generate the color chart in the NetLogo User Manual.4models/Code Examples/Communication-T-P Example.nlogoThis code example demonstrates Turtle-Patch communication. When a red turtle moves onto a patch, it turns the patch black. When a yellow turtle moves onto a patch, it turns the patch magenta.4models/Code Examples/Communication-T-T Example.nlogoThis code example is a simple demo of turtle-turtle communications. One turtle starts out with a message (the red turtle) and she spreads the message to other turtles.4models/Code Examples/Diffuse Off Edges Example.nlogoJNormally, the diffuse command diffuses the value of a variable over all of the patches equally. The total value of the variable across all patches remains constant. If wrapping is off, nothing special happens at the edge of the world. This code example shows to make the value disappear at or "fall off" the edges of the world.-models/Code Examples/File Input Example.nlogoZThis code example shows how to read in information from a file directly from NetLogo code..models/Code Examples/File Output Example.nlogoThis code example shows how to output information to an outside file directly from NetLogo code. All the data is written in human readable form using file-print.:models/Code Examples/Fully Connected Network Example.nlogoThis example shows how to make a fully connected network, that is, a network in which every node is linked to every other node.3models/Code Examples/GIS/GIS General Examples.nlogo\This model was built to test and demonstrate the functionality of the GIS NetLogo extension.3models/Code Examples/GIS/GIS Gradient Example.nlogo\This model was built to test and demonstrate the functionality of the GIS NetLogo extension.&models/Code Examples/GoGoMonitor.nlogoThis model communicates with the sensors and output ports of a GoGo board. A GoGo board is an open source, easy-to-build, low cost, general purpose circuit board designed for educational projects.3models/Code Examples/Grouping Turtles Example.nlogoThis example demonstrates two different methods for dividing an arbitrary number of turtles into groups, either by desired group size, or by desired number of groups.'models/Code Examples/Halo Example.nlogojThis example shows how to give a turtle a "halo", to make it stand out. The halo travels with the turtle.(models/Code Examples/Hatch Example.nlogo1This code example demonstrates the HATCH command.,models/Code Examples/Hex Cells Example.nlogoJThis demonstrates how to make a model that uses a hexagonal grid of cells..models/Code Examples/Hex Turtles Example.nlogolThis demonstrates how to have turtles move on a hexagonal lattice instead of NetLogo's usual square lattice.0models/Code Examples/Hill Climbing Example.nlogoThis example shows how to make turtles climb hills -- or descend into valleys -- using the UPHILL, UPHILL4, DOWNHILL, and DOWNHILL4 commands. The same technique is useful for modeling any kind of creature that follows a gradient in its environment.,models/Code Examples/Histogram Example.nlogo8This shows all of the code needed to create a histogram..models/Code Examples/HSB and RGB Example.nlogoxThis is a simple example of NetLogo colors versus RGB colors using APPROXIMATE-RGB and APPROXIMATE-HSB, and EXTRACT-RGB./models/Code Examples/Image Import Example.nlogoThis code example shows how to use, and the differences between, the IMPORT-PCOLORS, IMPORT-DRAWING, and IMPORT-PCOLORS-RGB primitives.5models/Code Examples/Intersecting Lines Example.nlogoOThis shows how to determine whether line segments cross, and if they do, where.5models/Code Examples/Intersecting Links Example.nlogo@This code example shows how to determine if two links intersect.1models/Code Examples/Label Position Example.nlogotThis example demonstrates a means of using the TIE command to make turtle labels you can position how you want them.:models/Code Examples/Lattice-Walking Turtles Example.nlogocThis example demonstrates how to create a hexagonal grid for turtles to walk around on using links.0models/Code Examples/Line of Sight Example.nlogoOn a perfectly flat landscape, you can see all the way to the horizon. But if the landscape has hills, your view of some of the land in front of you may be blocked. This code example shows how to simulate this using turtles moving over a patch landscape of varying elevation..models/Code Examples/Link Breeds Example.nlogoQThis code example shows how to create different kinds of links using link breeds./models/Code Examples/Link Lattice Example.nlogoThis example shows how to construct a regular lattice or mesh of links. Two kinds of lattice are demonstrated, a square lattice (where each node has four neighbors) and a hex lattice (where each node has six neighbors).7models/Code Examples/Link-Walking Turtles Example.nlogoaThis example shows how to make turtles "walk" from node to node on a network, by following links.-models/Code Examples/Look Ahead Example.nlogoThis code example shows how to have turtles look ahead before they move. By looking ahead, a turtle can determine what is in front of it and take a particular action. Looking ahead is most appropriate in situations where the turtle is not supposed to go "on top of" certain agents. This can be extremely useful for something like barriers or walls, which the turtle shouldn't move through.*models/Code Examples/Lottery Example.nlogoNetLogo makes it easy to make a random choice where every outcome is equally likely. But what if you want different outcomes to have different chances of being chosen...?5models/Code Examples/Mobile Aggregation Example.nlogoThis is a code example showing how to make clusters of turtles that move as a unit. In this example, whenever two turtles touch, their clusters merge.6models/Code Examples/Moore & Von Neumann Example.nlogoKThis model shows how to make Moore (square) and Von Neumann (diamond) neighborhoods of any radius. The built-in primitive NEIGHBORS gives you a Moore neighborhood of radius 1, and the built-in primitive NEIGHBORS4 gives you a Von Neumann neighborhood of radius 1, but for other radii you have to use the code like that given here.6models/Code Examples/Mouse Drag Multiple Example.nlogoOThis is an example of how to use the mouse to select and drag multiple turtles.1models/Code Examples/Mouse Drag One Example.nlogoZThis is a code sample illustrating how to let the user drag turtles around with the mouse.(models/Code Examples/Mouse Example.nlogoThis demo shows how to use the MOUSE-DOWN?, MOUSE-XCOR, and MOUSE-YCOR reporters to make a model that the user can interact with using the mouse. It also demonstrates the difference between using patches and turtles to achieve a desired effect.2models/Code Examples/Mouse Recording Example.nlogo*This is a demo presenting how to record and retrace movements of the mouse. When the "go" button is pressed, the user can draw one or more lines with the mouse by clicking and dragging the mouse around the view. Each set of drawn lines becomes a path along which a turtle travels, back and forth.6models/Code Examples/Move Towards Target Example.nlogo`This code example demonstrates how to have a turtle approach a target location a step at a time.(models/Code Examples/Movie Example.nlogo0This shows how to capture a movie of your model.)models/Code Examples/Myself Example.nlogoRThis model demonstrates several possible kinds of uses for the "myself" primitive.0models/Code Examples/Neighborhoods Example.nlogoThis code example shows how to use the basic neighborhood primitives. These include neighbors, neighbors4, in-radius, and at-points:*models/Code Examples/Network Example.nlogoThis example demonstrates how to make a network in NetLogo. The network consists of a collection of nodes, some of which are connected by links.1models/Code Examples/Network Import Example.nlogoThe code example provides an illustration of how to import network data from external files. This is useful when you have a specific network, perhaps created in another program or taken from real world data, that you would like to recreate in NetLogo.-models/Code Examples/Next Patch Example.nlogoThis code example demonstrates how to find out what patch a turtle would cross into next if it were to move forward continuously.7models/Code Examples/One Turtle Per Patch Example.nlogoIn some models, you want to allow only one turtle per patch. This example demonstrates a few different techniques for achieving this. This code example includes three strategies for moving turtles around while keeping the one turtle per patch satisfied.+models/Code Examples/Partners Example.nlogoThis code example shows how agents can "partner up" with each other. Each turtle will pair up with another turtle. Each turtle in a pair are aware of this partnership, preventing mismatched partners and multiple partners.1models/Code Examples/Patch Clusters Example.nlogoDThis example shows how to identify contiguous "clusters" of patches.4models/Code Examples/Patch Coordinates Example.nlogo The turtle goes forward "distance-of-travel" and returns to (start-x, start-y). The green patch is the center patch upon which there is a turtle at (start-x, start-y), and the patch "distance-of-travel" away from that center will flash as the turtle passes through it..models/Code Examples/Perspective Example.nlogoThis model shows how to see the world from different perspectives. It demonstrates the follow, watch, and reset-perspective commands.,models/Code Examples/Plot Axis Example.nlogo6This example shows how to draw an axis line on a plot.1models/Code Examples/Plot Smoothing Example.nlogoThis code example shows you how to plot a "smoothed" version of a jagged line. When you run the model, the black line is the original line, and the blue line is the smoothed version.+models/Code Examples/Plotting Example.nlogoThis shows all of the code needed to set up a plot which will display two variables as the model runs. In this case, the two variables are the x-coordinate and the y-coordinate of a turtle.+models/Code Examples/Profiler Example.nlogoThis code example demonstrates the functionality of the Profiler extension, which records the number of times user defined procedures are called, and how long they take to run.3models/Code Examples/Random Grid Walk Example.nlogo0This code example is a demo of a basic random walk, constrained to lie on a grid. At each step, the yellow turtle changes its heading randomly, but always in multiples of 90, so the turtle is always facing due north, east, south, or west. At each step, the turtle always lands on the center of a patch.1models/Code Examples/Random Network Example.nlogoThis shows how to create two different kinds of random networks. In an Erdos-Renyi network, each possible link is given a fixed probability of being created. In a simple random network, a fixed number of links are created between random nodes..models/Code Examples/Random Seed Example.nlogoKThis model shows how to use random seeds to create reproducible model runs..models/Code Examples/Random Walk Example.nlogorThis code example is a demo of a basic random walk. At each step, the yellow turtle changes its heading randomly./models/Code Examples/Rolling Plot Example.nlogocThis shows how to make a "rolling" plot, in which only the last n time steps of data are displayed..models/Code Examples/Scale-color Example.nlogoThis code example demonstrates the scale-color reporter. As a turtle's x-coordinate becomes larger,the turtle acquires a brighter color. Similarly, as a turtle's x-coordinate becomes smaller, the turtle acquires a darker shade. The center of the world is (0,0).*models/Code Examples/Scatter Example.nlogoThis code example shows three ways to scatter turtles across the world. One way scatters them evenly across the world. The second way scatters them in a circle. The third puts them on the center of random patches.2models/Code Examples/Shape Animation Example.nlogoThis code example shows how to use shapes to create animations. In this example, there is a walking person and growing flowers.(models/Code Examples/Sound/Beatbox.nlogoHere's a drum machine made with NetLogo. It uses the sound extension. You can make your own beats with it. Beats can be saved to disk and then loaded back in later.)models/Code Examples/Sound/Composer.nlogobComposer is a toy model that lets you write songs and play them using the NetLogo sound extension.2models/Code Examples/Sound/GasLab With Sound.nlogoThis model is included here in "Code Examples" as an example of taking an existing model and adding sound to it. It is based on the GasLab models, in the Chemistry & Physics section of the Models Library.7models/Code Examples/Sound/Musical Phrase Example.nlogoThis code example shows how PLAY-NOTE-LATER can be used to play a musical phrase without using START-NOTE and STOP-NOTE. This allows the model to continue running while the musical phrase plays.5models/Code Examples/Sound/Percussion Workbench.nlogoThis model demonstrates the capabilities of the NetLogo Sound Extension. It allows modelers to experiment with different drums.0models/Code Examples/Sound/Sound Workbench.nlogoThis model demonstrates the capabilities of the NetLogo Sound Extension. It allows modelers to experiment with different instruments.0models/Code Examples/State Machine Example.nlogo@This shows how to make your turtles into "state machines" using a turtle variable and the RUN command. A state machine consists of a collection of states with a different action associated with each state. The model itself is an alternate version of the Termites model located in the Biology section of Sample Models.-models/Code Examples/Tie System Example.nlogoThis example shows how to build a simple solar system using the tie command. You can explore the motion of the different heavenly bodies independently and combined./models/Code Examples/Transparency Example.nlogo2This example demonstrates transparency in NetLogo.%models/Code Examples/Tutorial 3.nlogoUThe construction of this model is described in Tutorial 3 in the NetLogo User Manual.3models/Code Examples/User Interaction Example.nlogoThis demonstrates the usage of NetLogo's user-interaction primitives, all of which begin with "user-". They let a model pop up a dialog box showing information to, or requesting information from, the model user..models/Code Examples/Vision Cone Example.nlogoThis example demonstrates how to give a turtle a "cone of vision" in front of it. It uses the IN-CONE primitive to filter an agentset according to whether the turtles or patches in it are in the calling turtle's cone of vision.1models/Code Examples/Wall Following Example.nlogoThe turtles in this example follow walls made out of colored patches. Some turtles try to keep the wall on their right; others keep the wall on their left.8models/Curricular Models/BEAGLE Evolution/Altruism.nlogoThis model (and Cooperation and Divide the Cake) are part of the EACH unit ("Evolution of Altruistic and Cooperative Habits: Learning About Complexity in Evolution"). See http://ccl.northwestern.edu/cm/EACH/ for more information on the EACH unit. The EACH unit is embedded within the BEAGLE (Biological Experiments in Adaptation, Genetics, Learning and Evolution) evolution curriculum. (See http://ccl.northwestern.edu/curriculum/simevolution/beagle.shtml).models/Curricular Models/BEAGLE Evolution/Bug Hunt Drift.nlogoThis is a genetic drift model that shows how gene frequencies change in a population due to purely random events. The effect of random selection of certain individuals in a population (either through death or through reproduction), results in the loss or gains of an allele. Over multiple generations this shift in gene distribution leads to alleles becoming more rare or more common (or disappearing completely) in a population. This effect is called genetic drift.?models/Curricular Models/BEAGLE Evolution/Bug Hunt Speeds.nlogoThis is a natural/artificial selection model that shows the result of two competing forces on natural selection of the speed of prey. Which force dominates depends on the behavior of predators.Fmodels/Curricular Models/BEAGLE Evolution/Bug Hunters Camouflage.nlogoThis is a HubNet activity of natural/artificial selection that shows how a population hunted by a predator can develop camouflaging. For example, in a forest with green leaves, green bugs may emerge as the predominant bug color.;models/Curricular Models/BEAGLE Evolution/Cooperation.nlogoThis model (and Altruism and Divide the Cake) are part of the EACH unit ("Evolution of Altruistic and Cooperative Habits: Learning About Complexity in Evolution"). See http://ccl.northwestern.edu/cm/EACH/ for more information on the EACH unit. The EACH unit is embedded within the BEAGLE (Biological Experiments in Adaptation, Genetics, Learning and Evolution) evolution curriculum. (See http://ccl.northwestern.edu/curriculum/simevolution/beagle.shtml).:models/Curricular Models/BEAGLE Evolution/Daisyworld.nlogo]This model explores the "Gaia hypothesis", which considers the Earth as a single, self-regulating system including both living and non-living parts. In particular, this model explores how living organisms both alter and are altered by climate, which is non-living. The example organisms are daisies and the climatic factor considered is temperature.Cmodels/Curricular Models/BEAGLE Evolution/GenDrift T interact.nlogo This model is an example of random selection. It shows that turtles that randomly exchange colors converge on a single color. The idea, explained in more detail in Dennett's "Darwin's Dangerous Idea", is that trait drifts can occur without any particular purpose or "selective pressure".;models/Curricular Models/BEAGLE Evolution/Guppy Spots.nlogoxThis selection model shows how sexual attraction and predation change the coloration and patterns in guppy's population.7models/Curricular Models/BEAGLE Evolution/Mimicry.nlogoBatesian mimicry is an evolutionary relationship in which a harmless species (the mimic) has evolved so that it looks very similar to a completely different species that isn't harmless (the model). A classic example of Batesian mimicry is the similar appearance of monarch butterflies and viceroy moths. Monarchs and viceroys are unrelated species that are both colored similarly -- bright orange with black patterns. Their colorations are so similar, in fact, that the two species are virtually indistinguishable from one another.Cmodels/Curricular Models/BEAGLE Evolution/Plant Hybridization.nlogo{This model lets you conduct experiments in Mendelian genetics with cross fertilization in a population of flowering plants.9models/Curricular Models/BEAGLE Evolution/Red Queen.nlogoThis model demonstrates the ideas of competitive co-evolution. In the model there are two species: frogs and snakes. The snakes are the only predators of the frogs, but the frogs produce a fast acting poison that kills the snakes before they can be eaten. However, the snakes have developed an anti-venom to counter the frog's poison. In this model, we assume that there are no other predators of the frogs, or prey that are consumed by the snakes. As such the two species enter a biological arms race in order to keep up with each other.Dmodels/Curricular Models/BEAGLE Evolution/Wolf Sheep Predation.nlogoThis model explores the stability of predator-prey ecosystems. Such a system is called unstable if it tends to result in extinction for one or more species involved. In contrast, a system is stable if it tends to maintain itself over time, despite fluctuations in population sizes.Rmodels/Curricular Models/Connected Chemistry/Connected Chemistry 1 Bike Tire.nlogo This model introduces the behavior of gas particles trapped in a fixed-volume container (such as a bike tire) or free and unbounded. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.Zmodels/Curricular Models/Connected Chemistry/Connected Chemistry 2 Changing Pressure.nlogo@This model explores the relationship between the number of gas particles in a fixed-volume container -- a bike tire -- and the pressure of the gas in that container. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.[models/Curricular Models/Connected Chemistry/Connected Chemistry 3 Circular Particles.nlogoThis model explores the relationship between particle kinetic energies during particle collisions. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.\models/Curricular Models/Connected Chemistry/Connected Chemistry 4 Number and Pressure.nlogo$This model explores the relationship between the number of gas particles and the pressure of the gas in a container with a fixed volume. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.amodels/Curricular Models/Connected Chemistry/Connected Chemistry 5 Temperature and Pressure.nlogo This model explores the relationship between the temperature of a gas and the pressure of a gas in a container with a fixed volume. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explores the behavior of gases.\models/Curricular Models/Connected Chemistry/Connected Chemistry 6 Volume and Pressure.nlogoThis model explores the relationship between the volume of a gas container and the pressure of a gas in that container. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.Vmodels/Curricular Models/Connected Chemistry/Connected Chemistry 7 Ideal Gas Law.nlogo7This model explores the relationship between the variables in the ideal gas law (number of particles, container volume, gas pressure, and gas temperature). This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explore the behavior of gases.]models/Curricular Models/Connected Chemistry/Connected Chemistry 8 Gas Particle Sandbox.nlogo2This model supports a drawing style interface for "sketching" up representations of new systems to explore related to gas behavior and gas particles. This model is part of the "Connected Chemistry" curriculum http://ccl.northwestern.edu/curriculum/ConnectedChemistry/ which explores the behavior of gases.,models/Curricular Models/EACH/Altruism.nlogoThis model (and Cooperation and Divide the Cake) are part of the EACH unit ("Evolution of Altruistic and Cooperative Habits: Learning About Complexity in Evolution"). See http://ccl.northwestern.edu/cm/EACH/ for more information on the EACH unit. The EACH unit is embedded within the BEAGLE (Biological Experiments in Adaptation, Genetics, Learning and Evolution) evolution curriculum. (See http://ccl.northwestern.edu/curriculum/simevolution/beagle.shtml)./models/Curricular Models/EACH/Cooperation.nlogoThis model (and Altruism and Divide the Cake) are part of the EACH unit ("Evolution of Altruistic and Cooperative Habits: Learning About Complexity in Evolution"). See http://ccl.northwestern.edu/cm/EACH/ for more information on the EACH unit. The EACH unit is embedded within the BEAGLE (Biological Experiments in Adaptation, Genetics, Learning and Evolution) evolution curriculum. (See http://ccl.northwestern.edu/curriculum/simevolution/beagle.shtml).>models/Curricular Models/EACH/Unverified/Divide The Cake.nlogoThis model (and Cooperation and Altruism) are part of the EACH curriculum: "Evolution of Altruistic and Cooperative Habits: Learning About Complexity in Evolution". See http://ccl.northwestern.edu/cm/EACH/ for more information.=models/Curricular Models/GasLab/GasLab Adiabatic Piston.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.7models/Curricular Models/GasLab/GasLab Atmosphere.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.5models/Curricular Models/GasLab/GasLab Free Gas.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.9models/Curricular Models/GasLab/GasLab Gas in a Box.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.8models/Curricular Models/GasLab/GasLab Gravity Box.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.>models/Curricular Models/GasLab/GasLab Isothermal Piston.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.;models/Curricular Models/GasLab/GasLab Maxwells Demon.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.=models/Curricular Models/GasLab/GasLab Single Collision.nlogoThis is one in a series of GasLab models that use the same basic rules for what happens when particles run into each other. Each one has different features in order to show different aspects of the behavior of gases.4models/Curricular Models/GasLab/GasLab Two Gas.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.Jmodels/Curricular Models/GasLab/Unverified/GasLab Circular Particles.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior. This model is different from the other GasLab models in that the collision calculations take the circular shape and size of the particles into account, instead of modeling the particles as dimensionless points.@models/Curricular Models/GasLab/Unverified/GasLab Heat Box.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.Emodels/Curricular Models/GasLab/Unverified/GasLab Moving Piston.nlogoThis model simulates the behavior of gas particles as the volume changes. In this model, the volume is slowly changing over time by a piston that is rising and falling. As the piston lowers, the volume of the box decreases and as the piston rises, the volume of the box increases. This systematic motion of the piston does no work on the particles inside the box. The piston only serves a mechanism to change the volume of the box.Dmodels/Curricular Models/GasLab/Unverified/GasLab Pressure Box.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.Bmodels/Curricular Models/GasLab/Unverified/GasLab Second Law.nlogoThis model is one in a series of GasLab models. They use the same basic rules for simulating the behavior of gases. Each model integrates different features in order to highlight different aspects of gas behavior.Nmodels/Curricular Models/MaterialSim/Unverified/MaterialSim Grain Growth.nlogoMost materials are not continuous arrangements of atoms, but rather composed of thousands or millions of microscopic crystals, known as grains. This model shows how the configuration and sizes of these grains change over time. Grain size is a very important characteristic for evaluating the mechanical properties of materials; it is exhaustively studied in metallurgy and materials science.6models/Curricular Models/NIELS/Current in a Wire.nlogoThis model shows a simplified microscopic picture of electrical conduction inside a wire connected across two battery terminals. It is based on Drude's free electron theory, and shows how electric current emerges from the collective movement of many electrons inside a wire.2models/Curricular Models/NIELS/Electron Sink.nlogo/This is a simplified model of electrical conduction based on Drude's free electron theory. It shows how electric current in a circuit consisting of a resistive wire connected across two terminals of a battery can be represented as a process of accumulation of free-electrons inside the battery-positive.3models/Curricular Models/NIELS/Electrostatics.nlogoThis model displays the common natural phenomenon expressed by the Coulomb's inverse-square law. It shows what happens when the strength of the force between two charges varies inversely with the square of the distance between them.5models/Curricular Models/NIELS/Parallel Circuit.nlogoThis model offers a microscopic view of electrical conduction in two wires that are connected in parallel to each other across two terminals of a battery. It shows that current in each wire is not always equal to current in the other wire, unlike in a series circuit (see Series Circuit model). However, since each of the wires is connected across the same battery terminals, voltage is the same in each wire.3models/Curricular Models/NIELS/Series Circuit.nlogoThis is a simplified, microscopic model of electrical conduction in a series circuit with two resistors (wires). It is based on Drude's free electron theory. The primary purpose of the model is to illustrate how electric current in one wire gets to be equal to electric current in the other even when the wires have different resistances: higher number of electrons moving slowly (towards the battery positive) in one wire, and fewer electrons moving faster in the other wire.:models/Curricular Models/ProbLab/4 Block Stalagmites.nlogo4-Block Stalagmites is part of the ProbLab middle-school curricular material for learning probability. Related materials are a random generator called a "marbles scooper" and a sample space called a "combinations tower". In classroom activities, students working with 4-Block Stalagmites will have interacted with the marbles box and built its sample space and thus would have inferred expectations as to outcome distributions in hypothetical experiments with the marbles box.>models/Curricular Models/ProbLab/4 Block Two Stalagmites.nlogoThis model is designed to help students understand the "shape" of the binomial distribution as resulting from how the elemental events are pooled into aggregate events. The model simulates a probability experiment that involves taking samples consisting of four independent binomial events that are each like a coin. Actual experimental outcomes from running this simulation are shown simultaneously in two representations./models/Curricular Models/ProbLab/4 Blocks.nlogom4-Blocks simulates an empirical probability experiment in which the randomness generator is a compound of 4 squares that each can independently be either green or blue. The model helps us conceptualize relations between theoretical and empirical aspects of the binomial function: combinatorial analysis (what we can get) and experimentation (what we actually get)./models/Curricular Models/ProbLab/9-Blocks.nlogo9-Blocks accompanies classroom work on the Combinations Tower, the giant bell-shaped histogram of all the 512 different green/blue combinations of the 3-by-3 array. Whereas building the Combinations Tower is a form of theoretical probability -- combinatorial analysis -- the 9-Block model complements with empirical probability of the same 3-by-3 object. In the plot window, a tall histogram grows that has the same shape as the Combinations Tower. How can that be? That is the theme question of this model.models/Curricular Models/ProbLab/Equidistant Probability.nlogoEquidistant Probability connects between probability and geometry. You select two or more squares, and the model searches randomly for squares that are equally distant from the squares you selected. To do this random search, creatures pop out of each one of your selected squares and simultaneously step forward one step in some random direction. If they all land in the same square, that's a hit. Can you guess how often this will happen?>models/Curricular Models/ProbLab/Expected Value Advanced.nlogoExpected Value Advanced illustrates expected-value analysis under the special condition that the sample size varies. This model extends the ProbLab model Expected Value, where the sample size is fixed.5models/Curricular Models/ProbLab/Expected Value.nlogoIn this model you run experiments that demonstrate the mathematical idea "expected value" (sometimes called "expectation value"). There is a set of different possible outcomes, and each of these outcomes has a different value. The model predicts the expected value based on the probabilities of each of these outcomes. The user can then take samples from the population and compare them to the values predicted by the model.3models/Curricular Models/ProbLab/Histo Blocks.nlogo1This model is a part of the ProbLab curriculum. The ProbLab Curriculum is currently under development at the Embodied Design Research Laboratory (EDRL), University of California, Berkeley. For more information about the ProbLab Curriculum please refer to http://ccl.northwestern.edu/curriculum/ProbLab/.>models/Curricular Models/ProbLab/Partition Perms Distrib.nlogo0Partition Permutation Distribution is a model built around the idea of a partition function. This function relates between an integer, e.g., 4, and the number of different ways you can break this integer up into groups of integers, where order does not matter. For instance, 4 can be broken up in 5 ways:8models/Curricular Models/ProbLab/Prob Graphs Basic.nlogoHProb Graphs Basic is a basic introduction to probability and statistics.7models/Curricular Models/ProbLab/ProbLab Genetics.nlogoThis model demonstrates some connections between probability and the natural sciences. Specifically, the model uses combinatorial space, sampling, and distribution in a genotype/phenotype analysis of fish procreation. The model allows you to look "under the hood": you can study a Mendel-type visualization of the combinations of dominant and recessive genes that underlie changes and trends in genetic distribution.models/Curricular Models/Urban Suite/Urban Suite - Cells.nlogoThis is a model of 2d cellular automata. It uses very simple rules to grow a form. These forms may be very complex, or highly regular.Kmodels/Curricular Models/Urban Suite/Urban Suite - Economic Disparity.nlogoThis model explores residential land-usage patterns from an economic perspective, using the socio-economic status of the agents to determine their preferences for choosing a location to live. It models the growth of two populations, one rich and one poor, who settle based on three properties of the landscape: the perceived quality, the cost of living, and the proximity to services (large red dots). These same properties then change based on where the different populations settle.Hmodels/Curricular Models/Urban Suite/Urban Suite - Path Dependence.nlogoRThis model explores the concept of path dependence as explained by W. Brian Arthur in his paper, "Urban Systems and Path Dependence" and several other of his papers. Essentially firms walk around a landscape looking for a place to settle. Several mechanisms of how they decide where to locate can be simulated, and the results examined.Bmodels/Curricular Models/Urban Suite/Urban Suite - Pollution.nlogoThis model is an examination of the fragile equilibrium of a predator-prey ecosystem. Populations of (1) people, (2) landscape elements and (3) swarms of airborne pollutant-agents compete for resources within an enclosed environment. Using this model, one can explore the behavior of the populations over time as they dynamically interact: the predators (pollution) and prey (people) can be compared over multiple generations as their populations demonstrate regular or irregular reproductive success.Jmodels/Curricular Models/Urban Suite/Urban Suite - Positive Feedback.nlogo2This model demonstrates the effect of "positive feedback". In particular, it is an implementation of the model described in the book "Cities and Complexity" by Michael Batty, on pages 38-42. For analysis and discussion beyond that provided with this model, the reader is encouraged to refer to this text.Bmodels/Curricular Models/Urban Suite/Urban Suite - Recycling.nlogoThis model demonstrates the relationship of agents (people) trying to sustain their natural resource of land over the course of time. In this simplified scenario, two types of developers exist: recyclers and wastefuls.Fmodels/Curricular Models/Urban Suite/Urban Suite - Sprawl Effect.nlogoThis model demonstrates a simplified version of city growth and how it leads to urban sprawl and the problems connected with it (e.g. leapfrogging). Since the rules by which the environment changes and the agents interact are quite simple, the strength of this model is less in attempting to realistically model urban development in detail, and more in demonstrating that certain patterns of behavior and land usage can emerge without requiring overly-complex rules.Tmodels/Curricular Models/Urban Suite/Urban Suite - Structure from Randomness 1.nlogo;This model demonstrates the concept of "structure from randomness". In particular, it is an implementation of the model described in the book "Cities and Complexity" by Michael Batty, on pages 43-45. For analysis and discussion beyond that provided with this model, the reader is encouraged to refer to this text.Tmodels/Curricular Models/Urban Suite/Urban Suite - Structure from Randomness 2.nlogoKThis is another model that demonstrates the concept of "structure from randomness". In particular, it is an implementation of the model described in the book "Cities and Complexity" by Michael Batty, on pages 45-47. For analysis and discussion beyond that provided with this model, the reader is encouraged to refer to this text.Lmodels/Curricular Models/Urban Suite/Urban Suite - Tijuana Bordertowns.nlogoThis model simulates various socio-economic realities of low-income residents of the City of Tijuana for the purpose of creating propositional design interventions.>models/HubNet Computer Activities/Bug Hunters Camouflage.nlogoThis is a HubNet activity of natural/artificial selection that shows how a population hunted by a predator can develop camouflaging. For example, in a forest with green leaves, green bugs may emerge as the predominant bug color.Nmodels/HubNet Computer Activities/Code Examples/Client Overrides Example.nlogo9This example demonstrates how to use overrides in HubNet.Pmodels/HubNet Computer Activities/Code Examples/Client Perspective Example.nlogoThis example demonstrates client perspectives: specifically, HUBNET-SEND-FOLLOW, HUBNET-SEND-WATCH, and HUBNET-RESET-PERSPECTIVE. These mirror FOLLOW, WATCH, and RESET-PERSPECTIVE, however, they only affect the view on the given client.>models/HubNet Computer Activities/Code Examples/Template.nlogoThis template contains code that can serve as a starting point for creating new HubNet activities. It shares many of the basic procedures used by other HubNet activities, which are required to connect to and communicate with clients in Disease-like activities.>models/HubNet Computer Activities/Dice Stalagmite HubNet.nlogo]Dice Stalagmite HubNet is a Participatory Simulation Activity (PSA) in probability for exploring dependent and independent events. Specifically, you compare the outcome distribution of a compound event, the sum of two randomly "rolled" dice, to the outcome distribution of independent events, the values of these same dice, taken one die at a time.7models/HubNet Computer Activities/Disease Doctors.nlogoThis model is a modified version of the Disease activity which, simulates the spread of a disease through a population. In this version the population can consist of students, which are turtles controlled by individual students via the HubNet Client, androids, infectable turtles controlled by the computer and doctors, un-infectable turtles that can heal other turtles. Doctors do not exist in the Disease activity./models/HubNet Computer Activities/Disease.nlogo'This model simulates the spread of a disease through a population. This population can consist of either students, which are turtles controlled by individual students via the HubNet Client, or turtles that are generated and controlled by NetLogo, called androids, or both androids and students.0models/HubNet Computer Activities/Gridlock.nlogoStudents control traffic lights in a real-time traffic simulation. The teacher controls overall variables, such as the speed limit and the number of cars. This allows students to explore traffic dynamics, which can lead into many areas of study, from calculus to social studies.5models/HubNet Computer Activities/Memory HubNet.nlogoThis is a HubNet version of the classic card game Memory. The game tests players' short term memory of where they last saw an image appear. Players can test different mental strategies for remembering./models/HubNet Computer Activities/Polling.nlogoThis model can be used to poll data from a set of students using HubNet Clients. The teacher can input questions to ask and then the students can input their choice in response to the question. The collective data can then be plotted.6models/HubNet Computer Activities/Root Beer Game.nlogoThis is an adaptation of a popular game created at MIT in the early 1960s that shows how small delays in a distribution system can create big problems. The participants take on one of four roles in a distribution network for root beer -- the factory, the distributor, the wholesaler, or the retailer. Each participant places and ships orders while trying to keep their costs to minimum. Costs include the holding inventory as well as missing out on sales because you produced too little root beer./models/HubNet Computer Activities/Sampler.nlogoSampler is a HubNet Participatory Simulation in statistics. It is part of the ProbLab curricular models. Students engage in statistical analysis as individuals and as a classroom. Through these activities, students discover the meaning and use of basic concepts in statistics.Emodels/HubNet Computer Activities/Tragedy of the Commons HubNet.nlogovThis model simulates the utilization of a common resource by multiple users. In this example, the common resource is represented by the common grazing area, used by goat farmers to feed their goats. Depending on the actions of the participants, the outcome may demonstrate a phenomenon called the "tragedy of the commons", where a common good or resource is over-utilized.;models/HubNet Computer Activities/Unverified/Function.nlogoIn this activity students can explore functions. Each student controls one point in the function. The activity supports several different kinds of exploration, with open ended possibilities for learning.Emodels/HubNet Computer Activities/Unverified/Gridlock Alternate.nlogoStudents control traffic lights in a real-time traffic simulation. The teacher controls overall variables, such as the speed limit and the number of cars. This allows students to explore traffic dynamics, which can lead into many areas of study, from calculus to social studies.>models/HubNet Computer Activities/Unverified/Guppy Spots.nlogoxThis selection model shows how sexual attraction and predation change the coloration and patterns in guppy's population.>models/HubNet Computer Activities/Unverified/Investments.nlogoThis model is a simple activity designed to teach compound interest. Students have a choice between investing their money with a teacher-controlled interest rate or using their money to purchase a car at a teacher defined price.Gmodels/HubNet Computer Activities/Unverified/Minority Game HubNet.nlogoMinority Game is a simplified model of an economic market. In each round agents choose to join one of two sides, 0 or 1. Those on the minority side at the end of a round earn a point. This game is inspired by the "El Farol" bar problem.Gmodels/HubNet Computer Activities/Unverified/Oil Cartel Alternate.nlogoThis activity explores the economics of a market with imperfect competition. As members of a cartel, participants experience how jointly determined price and quantity decisions can be advantageous to suppliers and harmful to consumers, but also why a cartel is so difficult to sustain. In this alternate version of Oil Cartel, members can also explicitly make investments to detect and penalize other members who "cheat" on their agreement, in order to explore the role of accurate information in maintaining a cartel.=models/HubNet Computer Activities/Unverified/Oil Cartel.nlogoThis is a collaborative exploration of the economics of a market with imperfect competition. As members of a cartel, participants experience how jointly determined price and quantity decisions can be advantageous to suppliers, harmful to consumers, but also why a cartel is so difficult to sustain. In this version of Oil Cartel, cartel members face differing profit expectations, and set production and pricing strategies in an attempt to meet those expectations. They respond to each other's behavior by altering their strategies.=models/HubNet Computer Activities/Unverified/PANDA BEAR.nlogo:Perimeters and Areas by Embodied Agent Reasoning, or PANDA BEAR, is a microworld for mathematics learning that lies at the intersection of dynamic geometry environments and participatory simulation activities. In PANDA BEAR, individual students identify with and control a single vertex of a shared, group-polygon.Cmodels/HubNet Computer Activities/Unverified/Polling Advanced.nlogoThis model can be used to poll data from a set of students using HubNet Clients. The teacher can input questions to ask and then the students can input their numerical choice (from 0 to 50) in response to the question. The collective data can then be plotted.Emodels/HubNet Computer Activities/Unverified/Predator Prey Game.nlogoThis model simulates a predator-prey relationship. The population consists of wolf packs (predators) and sheep herds (prey), some controlled by students via HubNet clients and some androids controlled by the computer. The wolves gain energy from consuming sheep, and the sheep gain energy from consuming grass (a primary producer). The model allows students to examine simple population dynamics like those modeled through the Lotka-Volterra equations in a participatory way.Kmodels/HubNet Computer Activities/Unverified/Prisoners Dilemma HubNet.nlogoThis model is a HubNet version of the Prisoner's Dilemma. The Prisoner's Dilemma is a famous game-theory situation that models the costs and benefits of collaboration or treason between free agents where there is a struggle over some capital.>models/HubNet Computer Activities/Unverified/Public Good.nlogoPublic Good is a game that asks each of the players to contribute to a common pool that will then be multiplied by the game leader and redistributed to all players.>models/HubNet Computer Activities/Unverified/Restaurants.nlogoThis simulates the competition in a a single industry, in this case the restaurant industry. Each restaurant is controlled by an owner trying to maximize profit. Depending on the owners' decisions, the outcome may demonstrate the Efficient Market Theorem ("Pareto efficiency"): if all the agents within a market look out for their own best interest, it will lead to the most efficient outcome. In this case it means that if the restaurant owners try to maximize their own wealth it will also maximize the customer satisfaction.:models/HubNet Computer Activities/Unverified/Walking.nlogoEach student defines the motion of a walking character by setting its velocity on their client over time intervals. The students have 9 different intervals for which they can set the velocity. They can then send these velocities to their characters, where they see the character walking its route over the 9 intervals. This is designed to help students understand the accumulation of distance as a function of time. This can serve as a jumping off point for advanced concepts ranging from derivatives and integrals to wave mechanics.6models/Perspective Demos/Ants (Perspective Demo).nlogosThis is a version of the Ants model, modified to show off NetLogo's perspective features. Try it in both 2D and 3D.:models/Perspective Demos/Flocking (Perspective Demo).nlogowThis is a version of the Flocking model, modified to show off NetLogo's perspective features. Try it in both 2D and 3D.Emodels/Perspective Demos/GasLab Gas in a Box (Perspective Demo).nlogoThis is a version of the GasLab Gas in a Box model, modified to show off NetLogo's perspective features. Try it in both 2D and 3D.:models/Perspective Demos/Termites (Perspective Demo).nlogowThis is a version of the Termites model, modified to show off NetLogo's perspective features. Try it in both 2D and 3D.1models/Sample Models/Art/Diffusion Graphics.nlogoDiffusion Graphics is unlike most other NetLogo models, in that it really doesn't 'model' anything. It simply explores the power behind an interesting patch primitive: 'diffuse'.(models/Sample Models/Art/Fireworks.nlogoThis program models the action of fireworks. Rockets begin at the bottom of the view, shoot upwards into the sky and then explode, emitting showers of falling sparks.'models/Sample Models/Art/Follower.nlogo{In Follower, turtles attempt to "connect" with other turtles, forming long chains according to a small set of simple rules.0models/Sample Models/Art/Optical Illusions.nlogo*This model presents six optical illusions.-models/Sample Models/Art/Sound Machines.nlogoJThis model shows one way turtles can make interesting and varied sounds, or if you like, music. It uses some simple physics to make "machines" that twist, spin, turn, twitch, and bounce. When a part of the machine touches a wall, ceiling, or floor, it makes a sound. The pitch of the sound depends on the location of the touch.models/Sample Models/Biology/Unverified/Tabonuco Yagrumo.nlogo"This is a system dynamics model of a simple ecosystem. Two species of trees -- tabonuco and yagrumo -- compete for space in a forest canopy. This model illustrates the role of hurricane destruction in this ecosystem, as well as the resultant nitrogen and carbon produced by the ecosystem.Kmodels/Sample Models/Biology/Unverified/Wolf Sheep Stride Inheritance.nlogoUThis model is a variation on the predator-prey ecosystems model wolf-sheep predation.(models/Sample Models/Biology/Virus.nlogoThis model simulates the transmission and perpetuation of a virus in a human population. Ecological biologists have suggested a number of factors which may influence the survival of a directly transmitted virus within a population. (Yorke, et al. "Seasonality and the requirements for perpetuation and eradication of viruses in populations." Journal of Epidemiology, volume 109, pages 103-123)7models/Sample Models/Biology/Wolf Sheep Predation.nlogoThis model explores the stability of predator-prey ecosystems. Such a system is called unstable if it tends to result in extinction for one or more species involved. In contrast, a system is stable if it tends to maintain itself over time, despite fluctuations in population sizes.Xmodels/Sample Models/Chemistry & Physics/Chemical Reactions/Acids and Bases/Buffer.nlogoThis model demonstrates the behavior of a buffered solution. A buffer is a solution that resists change in pH when either acid or base are added into it, within limits. It is best viewed as the third model in the ACID-BASE package.]models/Sample Models/Chemistry & Physics/Chemical Reactions/Acids and Bases/Strong Acid.nlogoThis model demonstrates how chemists and biologists measure the pH of a solution. The value of pH, like many other chemical measurements, emerges from the interactions and relative ratios of the composite molecules within a solution.jmodels/Sample Models/Chemistry & Physics/Chemical Reactions/Acids and Bases/Unverified/Diprotic Acid.nlogoSThis is the fourth model of the Acid-Base subsection of the Connected Chemistry models. It is best explored after the Strong Acid, Weak Acid, and Buffer models. In this model, we have yet another variant on determining the pH of a solution. This model depicts a diprotic acid, or an acid which can donate two atoms of hydrogen to a base.[models/Sample Models/Chemistry & Physics/Chemical Reactions/Acids and Bases/Weak Acid.nlogo}This model demonstrates the differences in the calculation of pH when evaluating a weak acid in solution. It is best viewed as the second model in the ACID-BASE package. Unlike a strong acid, a weak acid has a very low Ka (or acid dissociation constant). Consequently, very little of the acid is dissociated into hydronium ions and conjugate base as seen in the following reaction.Nmodels/Sample Models/Chemistry & Physics/Chemical Reactions/B-Z Reaction.nlogomodels/Sample Models/Chemistry & Physics/Solid Diffusion.nlogoFThis model describes how diffusion occurs between two adjacent solids.9models/Sample Models/Chemistry & Physics/Turbulence.nlogoThis model demonstrates the transition from order, or "laminarity", to disorder, or "turbulence" in fluids. Using a one-dimensional continuous cellular automaton, this model allows you to explore the relationship between turbulence, laminarity, and the viscosity of a fluid flowing through a "pipe." It also shows you how the roughness of pipes in which the fluid travels through affects the fluid's behavior.Dmodels/Sample Models/Chemistry & Physics/Unverified/Scattering.nlogoIThis project models the scattering of particles from a target that repels them. An example of this is the scattering of alpha particles (helium nuclei) from a heavy nucleus such as gold. This experiment, first done by Rutherford, provided important evidence that the positive charge in an atom is concentrated in a small place.Jmodels/Sample Models/Chemistry & Physics/Waves/Lattice Gas Automaton.nlogoThis model demonstrates circular wave propagation using a cellular automaton on a square grid. The behavior of the waves approximates the Navier-Stokes equation, a well established fluid dynamics equation discovered in 1823.9models/Sample Models/Chemistry & Physics/Waves/Rope.nlogo This project simulates a wave moving along a rope. The right end of the rope (shown in blue) is fixed to a wall. The left end of the rope (shown in green) provides an input, moving up and down in a sinusoidal motion. This creates a wave that travels along the rope.Gmodels/Sample Models/Chemistry & Physics/Waves/Unverified/Doppler.nlogoThis model demonstrates the Doppler effect, the apparent change in the frequency of a wave emitted by a source moving relative to an observer.Imodels/Sample Models/Chemistry & Physics/Waves/Unverified/Raindrops.nlogo[This model simulates raindrops falling on the surface of a pond and the waves they produce.Hmodels/Sample Models/Chemistry & Physics/Waves/Unverified/Speakers.nlogoWThis model simulates sound wave interference. There is one speaker at each end. A sinusoidal signal generator powers each speaker. The yellow line represents the sound level due to the left speaker, the cyan line represents the sound level due to the right speaker, and the red line represents the sum of the sound levels due to both speakers.Amodels/Sample Models/Chemistry & Physics/Waves/Wave Machine.nlogoThis model simulates wave motion in a membrane. The four edges of the membrane are fixed to a frame. A green rectangular area represents a driver plate that moves up and down, exhibiting sinusoidal motion.Jmodels/Sample Models/Computer Science/Cellular Automata/Brians Brain.nlogoThis program is an example of a two-dimensional cellular automaton. If you are not already familiar with 2D CA, see the model "Life" for a basic discussion.Nmodels/Sample Models/Computer Science/Cellular Automata/CA 1D Elementary.nlogoThis program models one-dimensional cellular automata. A cellular automaton (CA) is a computational machine that performs actions based on certain rules. The automaton is divided into cells, like the square cells of a checkerboard. Each cell can be either on or off (its "state"). The board is initialized with some cells on and some off. At each time step (or "tick") some rules "fire" and this results in some cells turning "on" and some turning "off".bmodels/Sample Models/Computer Science/Cellular Automata/CA 1D Simple Examples/CA 1D Rule 110.nlogoeThis program models one particular one-dimensional cellular automaton -- the one known as "rule 110".bmodels/Sample Models/Computer Science/Cellular Automata/CA 1D Simple Examples/CA 1D Rule 250.nlogoeThis program models one particular one-dimensional cellular automaton -- the one known as "rule 250".hmodels/Sample Models/Computer Science/Cellular Automata/CA 1D Simple Examples/CA 1D Rule 30 Turtle.nlogo!This program models one particular one-dimensional cellular automaton -- the one known as 'rule 30'. It is intended to be a companion model to the CA 1D Rule 30 model and to show an alternate way of modeling a cellular automaton -- by using turtles to do the processing instead of patches.amodels/Sample Models/Computer Science/Cellular Automata/CA 1D Simple Examples/CA 1D Rule 30.nlogodThis program models one particular one-dimensional cellular automaton -- the one known as "rule 30".amodels/Sample Models/Computer Science/Cellular Automata/CA 1D Simple Examples/CA 1D Rule 90.nlogodThis program models one particular one-dimensional cellular automaton -- the one known as "rule 90".Nmodels/Sample Models/Computer Science/Cellular Automata/CA 1D Totalistic.nlogo