Project_code_Matteo_Antonio_Inajetovic_CSNS2021.nlogo

;                                                                   Name:   Matteo Antonio Inajetovic
;                                                                        ID:     0000949648
;                                                                   Course: Artificial Intelligence

extensions [ nw ]

breed [computers computer]
directed-link-breed [ directed-edges directed-edge ]
undirected-link-breed [ undirected-edges undirected-edge ]

;;                                                                        ////    Variables   ////

computers-own
[
  infected?           ;; if true, the agent is infectious
  resistant?          ;; if true, the agent can't be infected
  virus-check-timer   ;; number of ticks since this computer's last virus-check
  dead?               ;; if true, the agent is dead.
  infected-ticks      ;; number of ticks since the computer has been infected
  age                 ;; age of the computer
  centrality-value    ;; centrality value for the computer
  immune-ticks        ;; number of ticks since the computer has become resistant
  control?            ;; a sample of computers can be checked to block the virus spread
  degree              ;; degree property of the agent used to build the function which gives the chance to choose where the infection will start
]

globals
[
  history   ;list of initial outbreak infected - computed for a visualization purpose
  infected  ;list of agents which transimitted the infection to other agents
  infect    ;list of agents get infected
  block     ;boolean variable to block the infected's out-links
  threshold ;centrality threshold
  vd        ;number of virus deaths
]
;;                                                                        ////    Setup section   ////
to setup
  clear-all

  ;global variables initialization
  set history []
  set infect []
  set infected []
  set block False

  set-current-plot "Degree distribution"


  setup-pa-network


  ask computers [
    set degree count link-neighbors
  ]

  ;; Initial Outbreak of the Virus
  initial-outbreak

  ;; Age random initialization
  ask computers [ set age random age-to-die - 200]

  ask links [ set color white  ]

  ; IIT tagging
  ask computers [ set control? False ]
  if isolation
  [
    ask n-of ( tool-efficiency * number-of-nodes / 100 ) computers  [ set control? True ]
    set threshold centrality-threshold  ;; computation of centrality threshold
  ]

  reset-ticks
end

;;                                                                        ////   Setup: Preferential Attachment Network   ////

to setup-pa-network
  make-node nobody          ;; first node, unattached
  make-node computer 0      ;; second node, attached to first node
  while [count computers < number-of-nodes ]
  [
    make-node find-partner
  ]
  ; make the network look a little prettier
  repeat 10
  [
    layout-spring computers links 0.3 (world-width / (sqrt number-of-nodes)) 1
    ;let factor sqrt count computers
    ;if factor = 0 [ set factor 1 ]
    ;layout-spring computers links (1 / factor) (14 / factor) (1.5 / factor)

  ]
  layout
end

to make-node [old-node]
  ;; function to allow the preferential attachment method to create the network by adding nodes
  set-default-shape computers "square"
  create-computers 1
  [
    ; for visual reasons, we don't put any nodes *too* close to the edges
    setxy (random-xcor * 0.95) (random-ycor * 0.95)
    become-susceptible
    set virus-check-timer random virus-check-frequency
    if old-node != nobody
      [
        ifelse enable-directed-links and not dead?
        [create-link-from old-node [ set color white ] if random 100 < 90 [create-link-to old-node [ set color white ]] ]
        [create-link-with old-node [ set color white ]]
        ;; position the new node near its partner
        move-to old-node
        fd 8
      ]
  ]
  layout
end


to-report find-partner
  report [one-of both-ends] of one-of links
end


to layout
  ;; the number 3 here is arbitrary; more repetitions slows down the
  ;; model, but too few gives poor layouts
  repeat 3 [
    ;; the more computers we have to fit into the same amount of space,
    ;; the smaller the inputs to layout-spring we'll need to use
    let factor sqrt count computers
    ;; numbers here are arbitrarily chosen for pleasing appearance
    layout-spring computers links (1 / factor) (7 / factor) (1 / factor)
    ;display  ;; for smooth animation
  ]
  ;; don't bump the edges of the world
  let x-offset max [xcor] of computers + min [xcor] of computers
  let y-offset max [ycor] of computers + min [ycor] of computers
  ;; big jumps look funny, so only adjust a little each time
  set x-offset limit-magnitude x-offset 1.0
  set y-offset limit-magnitude y-offset 1.0
  ask computers [ setxy (xcor - x-offset / 2) (ycor - y-offset / 2) ]

end

to-report limit-magnitude [number limit]
  if number > limit [ report limit ]
  if number < (- limit) [ report (- limit) ]
  report number
end

;;                                                                           ////    Go section   ////
to go
  if all? computers [not infected?]
    [ stop ]
  ask computers
  [
     set age age + 1
     set virus-check-timer virus-check-timer + 1
     set infected-ticks infected-ticks + 1
     if virus-check-timer >= virus-check-frequency
       [ set virus-check-timer 0 ]
  ]
  spread-virus    ;; Virus diffusion
  do-virus-checks ;; Virus checks, isolation part of the Tracing Tool and deaths caused by the virus.
  natural-death   ;; Some computers can leave the network because of "natural death", without the virus' intervention
  isolate         ;; The Infection Tracing Tool, at each timestep checks whether to block the tagged computers or not.
  new-computers   ;; At each timestep, new computers can join the network with a certain rate
  loss-resistants ;; Some computers can loose their resistance to the virus (SIRS model)
  tick
end

;;                                                                        ////  Computer's states   ////
to become-infected  ;; computer procedure
  set infected? true
  set resistant? false
  set color red
  set infected-ticks 1
  set dead? false

end

to become-susceptible  ;; computer procedure
  set infected? false
  set resistant? false
  set color blue
  ask my-links [ set color gray ]
  set infected-ticks 0
  set dead? false
end

to become-resistant  ;; computer procedure
  set infected? false
  set resistant? true
  set color green
  ask my-links [ set color gray ]
  set infected-ticks 0
  set dead? false
end

to become-dead ;; computer procedure
  set infected? false
  set resistant? false
  set dead? true
  set color gray - 3
  ask  my-links [ die ]
end

;;                                                                        ////    Functions' section   ////

to initial-outbreak
  ;; This function has been realized to give the opportunity to choose the region of the network where the initial infected nodes will be.
  ;; So the computation of all nodes' degree has not to be seen as a tool's property, it is only used for a studying purpose.

  let degree-list sort [count link-neighbors] of computers
  let deg-position (number-of-nodes - 5)
  let top-five item deg-position degree-list
  let hubs computers with [ degree > top-five ]
  let periphery  computers with [ degree < top-five ]
  let section "0"
  ifelse initial-infected  = "hubs"
    [set section hubs]
    [set section periphery]
  ask n-of initial-outbreak-size section
    [ become-infected
      set history lput who history]
end

to spread-virus ; S->I
  ask computers with [infected?]
    [ let origin who
      ask out-link-neighbors with [not resistant? and not infected? and not dead?]
        [ if random-float 100 < virus-spread-chance
        [ become-infected

            ;;    ---   IIT:  infection tracing    ----

          ask my-out-links [ set color red ]
          set infected lput who infected
          set infect lput origin infect
       ]
     ]
   ]
end


to isolate
  ;; IIT: if isolation is on and a "central" node is infected (its centrality value is higher
  ;; than the threshold given by the centrality-threshold function)
  ;; the boolean variable block is set to True and the infected outlinks are
  ;; canceled in order to avoid the virus spread

  ask computers with [infected?]
  [
    if centrality-value > threshold and isolation = True [
      set block True
    ]
  ]
end

to-report centrality-threshold
  ;; IIT: this function computes the beetweenness centrality
  ;; measure for all the sampled computers and store those values
  ;; in a sorted list. It returns a threshold value of
  ;; centrality.

  nw:set-context computers links;get-links-to-use
  ask computers with [ control? = True ] [
    set centrality-value (runresult [ -> nw:betweenness-centrality ])
  ]
  let blist []
  ask computers [ set blist lput centrality-value blist ]
  set blist sort blist
  let th-position (number-of-nodes - 5)  ;; the threshold is set to the fifth higher value of centrality
  let th item th-position blist
  print th
  report th
end


to loss-resistants
  ;; some resistant computers can become susceptible again
  ask computers with [ resistant? ] [
    set immune-ticks immune-ticks + 1
  ]

  ask computers with [control?  = False and resistant? and immune-ticks > temporary-immune-period ]
  ;;assumption: controlled computers cannot lose their resistance
  [
    if random 100 < loss-immune-rate
    [
      become-susceptible
      set immune-ticks 0
    ]

  ]

end

to do-virus-checks
  ;; IIT: isolation -> if the isolation tool is on, some infected computers
  ;; can be isolated by removing their outlinks, furthermore they cannot
  ;; send emails and spread the virus.

  ask computers with [infected? and  control? = True and virus-check-timer = 0 ]
  ;; only controlled computers can be blocked by the tool
  [
    if block and random 100 < 50 ;; 50% probability to succede in the block procedure.
          [ ask my-out-links [ die ]
            set color orange  ]
  ]

  ;;   I->R
  ;;   recovery section>
  ask computers with [infected? and virus-check-timer = 0]
  [
    if random 100 < recovery-chance
    [ become-resistant ]
  ]

  ;; computers which are infected for a certain time, without being recovered,
  ;; can die depending on the virus-death-rate slider.

  ask computers with [infected? and infected-ticks >= sick-ticks-to-die]
  [
    if random 100 < virus-death-rate
        [become-dead
         set vd vd + 1]
  ]
end

to natural-death
  ;; Some computers can leave the network because of "natural death", without the virus' influence
  ask computers with [ age >= age-to-die]
  [
    if random 100 < death-rate
        [become-dead]
  ]
end

to new-computers
  ;; At each timestep, new computers can join the network with a certain rate
  if random 100 < birth-rate [
    make-node
    find-partner
  ]
end

to infection-graph
  ;; Infection Graph or Transmission Network visualization
  clear-links
  clear-plot
  foreach history [ x ->
    ask computer x [set color yellow set shape "triangle"]
  ]
  foreach infected [ x ->
    ask computer x [set shape "circle"]
    ask computer x [set color yellow]
    let i position x infected
    let previous item i  infect
    ask computer x [ create-link-to computer previous [ set color red ] ]
    ]
  ask computers with [ color != yellow ] [ die ]
  let factor sqrt count computers
  if factor = 0 [ set factor 1 ]
  layout-spring computers links (1 / factor) (14 / factor) (1.5 / factor)
  ;let root-agent max-one-of computers [ count my-links ]
  ;layout-radial computers links root-agent
end

;;                                                             ////    Measures and tools from NW Extension    ////
to betweenness
  centrality [ -> nw:betweenness-centrality ]
end

to pagerank
  centrality [ -> nw:page-rank ]
end

to eigenvector
  centrality [ -> nw:eigenvector-centrality ]
end

to closeness
  centrality [ -> nw:closeness-centrality ]
end

to-report get-links-to-use
  report ifelse-value enable-directed-links
    [ directed-edges ]
    [ undirected-edges ]
end

to-report global-clustering-coefficient
  nw:set-context computers links
  let closed-triplets sum [ nw:clustering-coefficient * count my-links * (count my-links - 1) ] of computers
  let triplets sum [ count my-links * (count my-links - 1) ] of computers
  print closed-triplets
  print triplets
  report closed-triplets / triplets
end


to centrality [ measure ]
  nw:set-context computers links;get-links-to-use
  ask computers [
    let res (runresult measure) ; run the task for the computer
    ifelse is-number? res [
      set label precision res 2
      set size res ; this will be normalized later
    ]
    [
      set label res
      set size 1
    ]
  ]
  normalize-sizes-and-colors
end

to normalize-sizes-and-colors
  if count computers > 0 [
    let sizes sort [ size ] of computers ; initial sizes in increasing order
    let delta last sizes - first sizes ; difference between biggest and smallest
    ifelse delta = 0 [ ; if they are all the same size
      ask computers [ set size 1 ]
    ]
    [ ; remap the size to a range between 0.5 and 2.5
      ask computers [ set size ((size - first sizes) / delta) * 2 + 0.5 ]
    ]
    ask computers [ set color scale-color red size 0 5 ] ; using a higher range max not to get too white...
  ]
end
; Copyright 2008 Uri Wilensky.
; See Info tab for full copyright and license.
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@#$#@#$#@
## WHAT IS IT?

This model demonstrates the spread of a virus through a network.  Although the model is somewhat abstract, one interpretation is that each node represents a computer, and we are modeling the progress of a computer virus (or worm) through this network.  Each node may be in one of three states:  susceptible, infected, or resistant.  In the academic literature such a model is sometimes referred to as an SIR model for epidemics.

## HOW IT WORKS

Each time step (tick), each infected node (colored red) attempts to infect all of its neighbors.  Susceptible neighbors (colored green) will be infected with a probability given by the VIRUS-SPREAD-CHANCE slider.  This might correspond to the probability that someone on the susceptible system actually executes the infected email attachment.
Resistant nodes (colored gray) cannot be infected.  This might correspond to up-to-date antivirus software and security patches that make a computer immune to this particular virus.

Infected nodes are not immediately aware that they are infected.  Only every so often (determined by the VIRUS-CHECK-FREQUENCY slider) do the nodes check whether they are infected by a virus.  This might correspond to a regularly scheduled virus-scan procedure, or simply a human noticing something fishy about how the computer is behaving.  When the virus has been detected, there is a probability that the virus will be removed (determined by the RECOVERY-CHANCE slider).

If a node does recover, there is some probability that it will become resistant to this virus in the future (given by the GAIN-RESISTANCE-CHANCE slider).

When a node becomes resistant, the links between it and its neighbors are darkened, since they are no longer possible vectors for spreading the virus.

## HOW TO USE IT

Using the sliders, choose the NUMBER-OF-NODES and the AVERAGE-NODE-DEGREE (average number of links coming out of each node).

The network that is created is based on proximity (Euclidean distance) between nodes.  A node is randomly chosen and connected to the nearest node that it is not already connected to.  This process is repeated until the network has the correct number of links to give the specified average node degree.

The INITIAL-OUTBREAK-SIZE slider determines how many of the nodes will start the simulation infected with the virus.

Then press SETUP to create the network.  Press GO to run the model.  The model will stop running once the virus has completely died out.

The VIRUS-SPREAD-CHANCE, VIRUS-CHECK-FREQUENCY, RECOVERY-CHANCE, and GAIN-RESISTANCE-CHANCE sliders (discussed in "How it Works" above) can be adjusted before pressing GO, or while the model is running.

The NETWORK STATUS plot shows the number of nodes in each state (S, I, R) over time.

## THINGS TO NOTICE

At the end of the run, after the virus has died out, some nodes are still susceptible, while others have become immune.  What is the ratio of the number of immune nodes to the number of susceptible nodes?  How is this affected by changing the AVERAGE-NODE-DEGREE of the network?

## THINGS TO TRY

Set GAIN-RESISTANCE-CHANCE to 0%.  Under what conditions will the virus still die out?   How long does it take?  What conditions are required for the virus to live?  If the RECOVERY-CHANCE is bigger than 0, even if the VIRUS-SPREAD-CHANCE is high, do you think that if you could run the model forever, the virus could stay alive?

## EXTENDING THE MODEL

The real computer networks on which viruses spread are generally not based on spatial proximity, like the networks found in this model.  Real computer networks are more often found to exhibit a "scale-free" link-degree distribution, somewhat similar to networks created using the Preferential Attachment model.  Try experimenting with various alternative network structures, and see how the behavior of the virus differs.

Suppose the virus is spreading by emailing itself out to everyone in the computer's address book.  Since being in someone's address book is not a symmetric relationship, change this model to use directed links instead of undirected links.

Can you model multiple viruses at the same time?  How would they interact?  Sometimes if a computer has a piece of malware installed, it is more vulnerable to being infected by more malware.

Try making a model similar to this one, but where the virus has the ability to mutate itself.  Such self-modifying viruses are a considerable threat to computer security, since traditional methods of virus signature identification may not work against them.  In your model, nodes that become immune may be reinfected if the virus has mutated to become significantly different than the variant that originally infected the node.

## RELATED MODELS

Virus, Disease, Preferential Attachment, Diffusion on a Directed Network

## NETLOGO FEATURES

Links are used for modeling the network.  The `layout-spring` primitive is used to position the nodes and links such that the structure of the network is visually clear.

Though it is not used in this model, there exists a network extension for NetLogo that you can download at: https://github.com/NetLogo/NW-Extension.

## HOW TO CITE

If you mention this model or the NetLogo software in a publication, we ask that you include the citations below.

For the model itself:

* Stonedahl, F. and Wilensky, U. (2008).  NetLogo Virus on a Network model.  http://ccl.northwestern.edu/netlogo/models/VirusonaNetwork.  Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

Please cite the NetLogo software as:

* Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

## COPYRIGHT AND LICENSE

Copyright 2008 Uri Wilensky.

![CC BY-NC-SA 3.0](http://ccl.northwestern.edu/images/creativecommons/byncsa.png)

This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License.  To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.

Commercial licenses are also available. To inquire about commercial licenses, please contact Uri Wilensky at uri@northwestern.edu.

<!-- 2008 Cite: Stonedahl, F. -->
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car
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Circle -16777216 true false 30 180 90
Polygon -16777216 true false 162 80 132 78 134 135 209 135 194 105 189 96 180 89
Circle -7500403 true true 47 195 58
Circle -7500403 true true 195 195 58

circle
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Circle -7500403 true true 0 0 300

circle 2
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Circle -7500403 true true 0 0 300
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cow
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Polygon -7500403 true true 200 193 197 249 179 249 177 196 166 187 140 189 93 191 78 179 72 211 49 209 48 181 37 149 25 120 25 89 45 72 103 84 179 75 198 76 252 64 272 81 293 103 285 121 255 121 242 118 224 167
Polygon -7500403 true true 73 210 86 251 62 249 48 208
Polygon -7500403 true true 25 114 16 195 9 204 23 213 25 200 39 123

cylinder
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Circle -7500403 true true 0 0 300

dot
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Circle -7500403 true true 90 90 120

face happy
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Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Polygon -16777216 true false 150 255 90 239 62 213 47 191 67 179 90 203 109 218 150 225 192 218 210 203 227 181 251 194 236 217 212 240

face neutral
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Circle -7500403 true true 8 7 285
Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Rectangle -16777216 true false 60 195 240 225

face sad
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0
Circle -7500403 true true 8 8 285
Circle -16777216 true false 60 75 60
Circle -16777216 true false 180 75 60
Polygon -16777216 true false 150 168 90 184 62 210 47 232 67 244 90 220 109 205 150 198 192 205 210 220 227 242 251 229 236 206 212 183

fish
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Polygon -1 true false 44 131 21 87 15 86 0 120 15 150 0 180 13 214 20 212 45 166
Polygon -1 true false 135 195 119 235 95 218 76 210 46 204 60 165
Polygon -1 true false 75 45 83 77 71 103 86 114 166 78 135 60
Polygon -7500403 true true 30 136 151 77 226 81 280 119 292 146 292 160 287 170 270 195 195 210 151 212 30 166
Circle -16777216 true false 215 106 30

flag
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0
Rectangle -7500403 true true 60 15 75 300
Polygon -7500403 true true 90 150 270 90 90 30
Line -7500403 true 75 135 90 135
Line -7500403 true 75 45 90 45

flower
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Polygon -10899396 true false 135 120 165 165 180 210 180 240 150 300 165 300 195 240 195 195 165 135
Circle -7500403 true true 85 132 38
Circle -7500403 true true 130 147 38
Circle -7500403 true true 192 85 38
Circle -7500403 true true 85 40 38
Circle -7500403 true true 177 40 38
Circle -7500403 true true 177 132 38
Circle -7500403 true true 70 85 38
Circle -7500403 true true 130 25 38
Circle -7500403 true true 96 51 108
Circle -16777216 true false 113 68 74
Polygon -10899396 true false 189 233 219 188 249 173 279 188 234 218
Polygon -10899396 true false 180 255 150 210 105 210 75 240 135 240

house
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Rectangle -7500403 true true 45 120 255 285
Rectangle -16777216 true false 120 210 180 285
Polygon -7500403 true true 15 120 150 15 285 120
Line -16777216 false 30 120 270 120

leaf
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Polygon -7500403 true true 150 210 135 195 120 210 60 210 30 195 60 180 60 165 15 135 30 120 15 105 40 104 45 90 60 90 90 105 105 120 120 120 105 60 120 60 135 30 150 15 165 30 180 60 195 60 180 120 195 120 210 105 240 90 255 90 263 104 285 105 270 120 285 135 240 165 240 180 270 195 240 210 180 210 165 195
Polygon -7500403 true true 135 195 135 240 120 255 105 255 105 285 135 285 165 240 165 195

line
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Line -7500403 true 150 0 150 300

line half
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Line -7500403 true 150 0 150 150

pentagon
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Polygon -7500403 true true 150 15 15 120 60 285 240 285 285 120

person
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0
Circle -7500403 true true 110 5 80
Polygon -7500403 true true 105 90 120 195 90 285 105 300 135 300 150 225 165 300 195 300 210 285 180 195 195 90
Rectangle -7500403 true true 127 79 172 94
Polygon -7500403 true true 195 90 240 150 225 180 165 105
Polygon -7500403 true true 105 90 60 150 75 180 135 105

plant
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Rectangle -7500403 true true 135 90 165 300
Polygon -7500403 true true 135 255 90 210 45 195 75 255 135 285
Polygon -7500403 true true 165 255 210 210 255 195 225 255 165 285
Polygon -7500403 true true 135 180 90 135 45 120 75 180 135 210
Polygon -7500403 true true 165 180 165 210 225 180 255 120 210 135
Polygon -7500403 true true 135 105 90 60 45 45 75 105 135 135
Polygon -7500403 true true 165 105 165 135 225 105 255 45 210 60
Polygon -7500403 true true 135 90 120 45 150 15 180 45 165 90

square
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0
Rectangle -7500403 true true 30 30 270 270

square 2
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0
Rectangle -7500403 true true 30 30 270 270
Rectangle -16777216 true false 60 60 240 240

star
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0
Polygon -7500403 true true 151 1 185 108 298 108 207 175 242 282 151 216 59 282 94 175 3 108 116 108

target
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0
Circle -7500403 true true 0 0 300
Circle -16777216 true false 30 30 240
Circle -7500403 true true 60 60 180
Circle -16777216 true false 90 90 120
Circle -7500403 true true 120 120 60

tree
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0
Circle -7500403 true true 118 3 94
Rectangle -6459832 true false 120 195 180 300
Circle -7500403 true true 65 21 108
Circle -7500403 true true 116 41 127
Circle -7500403 true true 45 90 120
Circle -7500403 true true 104 74 152

triangle
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0
Polygon -7500403 true true 150 30 15 255 285 255

triangle 2
false
0
Polygon -7500403 true true 150 30 15 255 285 255
Polygon -16777216 true false 151 99 225 223 75 224

truck
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0
Rectangle -7500403 true true 4 45 195 187
Polygon -7500403 true true 296 193 296 150 259 134 244 104 208 104 207 194
Rectangle -1 true false 195 60 195 105
Polygon -16777216 true false 238 112 252 141 219 141 218 112
Circle -16777216 true false 234 174 42
Rectangle -7500403 true true 181 185 214 194
Circle -16777216 true false 144 174 42
Circle -16777216 true false 24 174 42
Circle -7500403 false true 24 174 42
Circle -7500403 false true 144 174 42
Circle -7500403 false true 234 174 42

turtle
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0
Polygon -10899396 true false 215 204 240 233 246 254 228 266 215 252 193 210
Polygon -10899396 true false 195 90 225 75 245 75 260 89 269 108 261 124 240 105 225 105 210 105
Polygon -10899396 true false 105 90 75 75 55 75 40 89 31 108 39 124 60 105 75 105 90 105
Polygon -10899396 true false 132 85 134 64 107 51 108 17 150 2 192 18 192 52 169 65 172 87
Polygon -10899396 true false 85 204 60 233 54 254 72 266 85 252 107 210
Polygon -7500403 true true 119 75 179 75 209 101 224 135 220 225 175 261 128 261 81 224 74 135 88 99

wheel
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0
Circle -7500403 true true 3 3 294
Circle -16777216 true false 30 30 240
Line -7500403 true 150 285 150 15
Line -7500403 true 15 150 285 150
Circle -7500403 true true 120 120 60
Line -7500403 true 216 40 79 269
Line -7500403 true 40 84 269 221
Line -7500403 true 40 216 269 79
Line -7500403 true 84 40 221 269

x
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0
Polygon -7500403 true true 270 75 225 30 30 225 75 270
Polygon -7500403 true true 30 75 75 30 270 225 225 270
@#$#@#$#@
NetLogo 6.1.1
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
default
0.0
-0.2 0 0.0 1.0
0.0 1 1.0 0.0
0.2 0 0.0 1.0
link direction
true
0
Line -7500403 true 150 150 90 180
Line -7500403 true 150 150 210 180
@#$#@#$#@
0
@#$#@#$#@