AlexIsmodesThreeAgentPredationModel.nlogo

globals
[
  max-humans ;
  max-wolves
  max-rabbits

  rabbit-sensing-radius
  wolf-sensing-radius
  human-sensing-radius
]
; Humans, wolves, and rabbits are the three different breeds of turtles
breed [ humans human ]
breed [ wolves wolf ]
breed [ rabbits rabbit ]
turtles-own [ energy gender age birth-tick lifetime hmyclosest hmynext wmyclosest wmynext rmyclosest rmynext]
patches-own [ countdown ]


to setup
  clear-all

  ; Check model-version switch
  ; if we're not modeling grass, then the sheep don't need to eat to survive
  ; otherwise the grass's state of growth and growing logic need to be set up
  ifelse model-version = "sheep-wolves-grass" [
    ask patches [
      set pcolor one-of [ green brown ]
      ifelse pcolor = green
        [ set countdown grass-regrowth-time ]
      [ set countdown random grass-regrowth-time ] ; initialize grass regrowth clocks randomly for brown patches
    ]
  ]
  [
    ask patches [ set pcolor green ]
  ]

  create-rabbits initial-number-rabbits  ; create the rabbits, then initialize their variables
  [
    set rmyclosest 0
    set shape  "rabbit"
    set color white
    set size 1.5
    set label-color blue - 2
    set lifetime rabbit-lifetime
    set age 0
    set rabbit-sensing-radius rabbit-mate-distance
    set energy random (2 * rabbit-gain-from-food)
    setxy random-xcor random-ycor
    ifelse random 2 = 1
    [ set gender "male" ]
    [ set gender "female" ]
  ]

  create-wolves initial-number-wolves  ; create the wolves, then initialize their variables
  [

    set wmyclosest 0
    set shape "wolf"
    set color 3.5
    set size 2
    set lifetime 15
    set age 0
    set wolf-sensing-radius wolf-mate-distance
    set energy random (2 * wolf-gain-from-food)
    setxy random-xcor random-ycor
    ifelse random 2 = 1
    [ set gender "male" ]
    [ set gender "female" ]
  ]

   create-humans initial-number-humans  ; create the humans, then initialize their variables
  [

    set hmyclosest 0
    set shape  "person"
    set color black
    set lifetime 70
    set age 0
    set human-sensing-radius human-mate-distance
    set size 2.5  ; easier to see
    set energy random (2 * human-gain-from-food)
    setxy random-xcor random-ycor
    ifelse random 2 = 1
    [ set gender "male" ]
    [ set gender "female" ]
  ]
  display-labels
  reset-ticks
end

to r-choose-neighbors
  ;if not any? rabbits and count humans > max-humans
  if count rabbits >= 2
      [
      ask rabbits
        [
          set rmynext min-one-of other rabbits [distance myself]  ;; choose my nearest neighbor based on distance
          set rmyclosest distance rmynext
        ]
  ]
end


to w-choose-neighbors
  ;if not any? rabbits and count humans > max-humans
  if count wolves >= 2
      [
      ask wolves
        [
          set wmynext min-one-of other wolves [distance myself]  ;; choose my nearest neighbor based on distance
          set wmyclosest distance wmynext
        ]
  ]
end


to h-choose-neighbors
  ;if not any? rabbits and count humans > max-humans
  if count humans >= 2
      [
      ask humans
        [
          set hmynext min-one-of other humans [distance myself]  ;; choose my nearest neighbor based on distance
          set hmyclosest distance hmynext
        ]
  ]
end


to aging
 set age age + 1
end

;testing!

to go
  ; stop the simulation of no humans, wolves or rabbits
  if not any? turtles [ stop ]
  ; stop the model if there are no humans or no wolves or no rabbits and stop if the number of humans or wolves or rabbits gets too large

  ;if not any? rabbits and if not any? wolves
  ;[ user-message "The humans have inherited the earth" stop ]

  if count rabbits = 0 and count wolves = 0 [ user-message "The humans have inherited the earth" stop ]
  if count rabbits = 0 and count humans = 0 [ user-message "The wolves have inherited the earth" stop ]
  if count wolves = 0 and count humans = 0 [ user-message "The rabbits have inherited the earth" stop ]

  ;if not any? rabbits and if not any? humans
  ;[ user-message "The wolves have inherited the earth" stop ]

  ;if not any? wolves and if not any? humans
  ;[ user-message "The rabbits have inherited the earth" stop ]


  ;if not any? wolves and count rabbits > max-rabbits [ user-message "The rabbits have inherited the earth" stop ]


  r-choose-neighbors
  w-choose-neighbors
  h-choose-neighbors



  ask rabbits [
    move-rabbit
    if model-version = "rabbits-wolves-humans" [
      set energy energy - 1  ; deduct energy for rabbits only if running rabbits-wolves-humans model version
      eat-grass  ; rabbits eat grass only if running rabbits-wolves-humans model version
      death ; rabbits die if out of energy
    ]
    reproduce-rabbits  ; sheep reproduce at random rate governed by slider
  ]

  ask wolves [
    move
    set energy energy - 1  ; wolves lose energy as they move
    w-eat-rabbits ; wolves eat a rabbit on their patch
    death ; wolves die if out of energy
    reproduce-wolves ; wolves reproduce at random rate governed by slider
  ]

  ask humans [
    move
    set energy energy - 1  ; humans lose energy as they move
    repeat 5 [ shoot-eat-rabbits ]
    shoot-wolves ; wolves eat a sheep on their patch
    death ; humans die if out of energy
    reproduce-humans ; wolves reproduce at random rate governed by slider
  ]

  if model-version = "sheep-wolves-grass" [ ask patches [ grow-grass ] ]
  ; set grass count patches with [pcolor = green]
  display-labels

  ask turtles [aging]
  ask patches [  grow-grass ]

  tick

end

to move  ; turtle procedure
  rt random 50
  lt random 50
  fd 1
end

to move-rabbit
  let target one-of patches with [  pcolor = green ]
  if is-patch? target [ move-to target ]
end

to eat-grass  ; sheep procedure
  ; sheep eat grass, turn the patch brown
  if pcolor = green [
    set pcolor brown
    set energy energy + rabbit-gain-from-food  ; sheep gain energy by eating
  ]
end

to-report potential-mate-rabbit
  ; this is a reporter that gets called in the
  ; context of a rabbit looking for potential mates
  let prospects other rabbits in-radius rabbit-sensing-radius ; rabbit-sensing-radius

  ; - if potential mate already has another mate
  ; - how recently it has reproduced ...
  ; - think about sex: have a turtles-own variable for sex that indicates
  ; male vs. female so mates must be opposite

  ; narrow down prospects to only include those of the opposite gender to the current rabbit (myself).
  set prospects prospects with [ gender != [gender] of myself ] ; select only prospects with the opposite gender
  ; select for other attributes, such as not having a mate and whether it's reproduced recently ...
  ; once you've narrowed this down, we can report one of the remaining prospects:
  report one-of prospects ; if there are no prospects, this will report nobody

end


to-report potential-mate-wolf
  ; this is a reporter that gets called in the
  ; context of a wolf looking for potential mates
 let prospects other wolves in-radius wolf-sensing-radius ; wolf-sensing-radius

  ; - if potential mate already has another mate
  ; - how recently it has reproduced ...
  ; - think about sex: have a turtles-own variable for sex that indicates
  ; male vs. female so mates must be opposite

  ; narrow down prospects to only include those of the opposite gender to the current wolf (myself).
  set prospects prospects with [ gender != [gender] of myself ] ; select only prospects with the opposite gender
  ; select for other attributes, such as not having a mate and whether it's reproduced recently ...
  ; once you've narrowed this down, we can report one of the remaining prospects:
  report one-of prospects ; if there are no prospects, this will report nobody

end


to-report potential-mate-human
  ; this is a reporter that gets called in the
  ; context of a human looking for potential mates
 let prospects other humans in-radius human-sensing-radius ; human-sensing-radius

  ; - if potential mate already has another mate
  ; - how recently it has reproduced ...
  ; - think about sex: have a turtles-own variable for sex that indicates
  ; male vs. female so mates must be opposite

  ; narrow down prospects to only include those of the opposite gender to the current wolf (myself).
  set prospects prospects with [ gender != [gender] of myself ] ; select only prospects with the opposite gender
  ; select for other attributes, such as not having a mate and whether it's reproduced recently ...
  ; once you've narrowed this down, we can report one of the remaining prospects:
  report one-of prospects ; if there are no prospects, this will report nobody

end


to reproduce-rabbits  ; rabbit procedure
  let mate potential-mate-rabbit

  if mate != nobody and random-float 100 < rabbit-reproduce
  [
    move-to [patch-here] of mate
    set energy energy * 0.75
    ask mate [ set energy energy * 0.75 ]
    hatch 1 [
      set energy 0.25 * ([ energy ] of myself + [energy] of mate)
      set age 0
      ifelse random 2 = 1
      [ set gender "male"]
      [ set gender "female" ]
      rt random-float 360
      fd 1
    ]
  ]
end

to reproduce-wolves  ; wolf procedure
  let mate potential-mate-wolf

  if mate != nobody and random-float 100 < wolf-reproduce
  [
    move-to [patch-here] of mate
    set energy energy * 0.75
    ask mate [ set energy energy * 0.75 ]
    hatch 1 [
      set age 0
      set energy 0.25 * ([ energy ] of myself + [energy] of mate)
      ifelse random 2 = 1
      [ set gender "male"]
      [ set gender "female" ]
      rt random-float 360
      fd 1
    ]
  ]
end

to reproduce-humans  ; human procedure
  let mate potential-mate-human

  if mate != nobody and random-float 100 < human-reproduce
  [
    move-to [patch-here] of mate
    set energy energy * 0.75
    ask mate [ set energy energy * 0.75 ]
    hatch 1 [
      set age 0
      set energy 0.25 * ([ energy ] of myself + [energy] of mate)
      ifelse random 2 = 1
      [ set gender "male"]
      [ set gender "female" ]
      rt random-float 360
      fd 1
    ]
  ]
end

to w-eat-rabbits  ; WOLF KILL/EAT RABBIT
  let preyisrabbit one-of rabbits in-radius wolf-hunt-distance
  if preyisrabbit != nobody  [                          ; did we get one?  if so,
    ask preyisrabbit [ die ]                            ; kill it, and...
    set energy energy + wolf-gain-from-food     ; get energy from eating
  ]
end

to w-eat-humans  ; WOLF KILL/EAT HUMAN
  let preyishuman one-of humans-here
  if preyishuman != nobody  [                          ; did we get one?  if so,
    ask preyishuman [ die ]                            ; kill it, and...
    set energy energy + wolf-gain-from-food     ; get energy from eating
  ]
end

to-report potential-shot-rabbit ; HUMAN IDENTIFY POTENTIAL SHOT RABBIT
  ; this is a reporter that gets called in the
  ; context of a human shooting a nearby wolf
  let prospects rabbits in-radius 10 ;human-sensing-radius
  ; this is just a place-holder and you should replace it with yur
  ; code for finding a potential mate
  ; You might consider whether the potential mate already has another
  ; mate or how recently it has reproduced ...
  ; also think about sex: have a turtles-own variable for sex that indicates
  ; male vs. female so mates must be opposite

    report one-of prospects

end

to shoot-eat-rabbits  ; HUMAN KILL/EAT RABBIT
  let preyisrabbit potential-shot-rabbit
  if preyisrabbit != nobody and shooting-accuracy > random-float 100 [
    ask preyisrabbit [ die ]                            ; kill it, and...
    set energy energy + human-gain-from-food     ; get energy from eating
  ]
end

to-report potential-shot-wolf ; HUMAN IDENTIFY POTENTIAL SHOT WOLF
  ; this is a reporter that gets called in the
  ; context of a human shooting a nearby wolf
  let prospects other wolves in-radius 5 ;human-sensing-radius
  ; this is just a place-holder and you should replace it with yur
  ; code for finding a potential mate
  ; You might consider whether the potential mate already has another
  ; mate or how recently it has reproduced ...
  ; also think about sex: have a turtles-own variable for sex that indicates
  ; male vs. female so mates must be opposite

   report one-of prospects

end

to shoot-wolves ; HUMAN KILL WOLF
 let preyiswolf potential-shot-wolf

  if preyiswolf != nobody and shooting-accuracy > random-float 100 [
  ask preyiswolf [die]
  ]
end

to death  ; turtle procedure (i.e. both wolf nd sheep procedure)
  ; when energy dips below zero, die
  if energy < 0 [ die ]
  if random-float 1.0 < (0.75 * (age / lifetime) ^ 4)
  [ die ]
end

to grow-grass  ; patch procedure
  ; countdown on brown patches: if reach 0, grow some grass
  if pcolor = brown [
    ifelse countdown <= 0
      [ set pcolor green
        set countdown grass-regrowth-time ]
      [ set countdown countdown - 1 ]
  ]
end

to-report grass
  ifelse model-version = "rabbits-wolves-humans" [
    report patches with [pcolor = green]
  ]
  [ report 0 ]
end


to display-labels
  ask turtles [ set label "" ]
  if show-energy? [
    ask wolves [ set label round energy ]
    if model-version = "rabbits-wolves-humans" [ ask rabbits [ set label round energy ] ]
  ]
end

to-report survivors
  ifelse any? humans
  [
    report "humans"
  ]
  [
    ifelse any? wolves
    [ report "wolves" ]
    [ report "rabbits" ]
  ]
end


; Modified Uri Wilensky's Wolf-Sheep Predation Model (1997)
; Modification called "Three-Agent Predation Model" by Alex Ismodes (2019)
@#$#@#$#@
GRAPHICS-WINDOW
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9.804
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ticks
30.0

SLIDER
515
40
680
73
initial-number-humans
initial-number-humans
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15.0
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NIL
HORIZONTAL

SLIDER
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80
330
113
rabbit-gain-from-food
rabbit-gain-from-food
0.0
50.0
17.0
1.0
1
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HORIZONTAL

SLIDER
175
120
330
153
rabbit-reproduce
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SLIDER
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SLIDER
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wolf-gain-from-food
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HORIZONTAL

SLIDER
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SLIDER
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BUTTON
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setup
setup
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1
T
OBSERVER
NIL
NIL
NIL
NIL
1

BUTTON
85
170
170
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go
go
T
1
T
OBSERVER
NIL
NIL
NIL
NIL
0

PLOT
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695
Populations
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pop.
0.0
100.0
0.0
100.0
true
true
"" ""
PENS
"rabbits / 100" 1.0 0 -1264960 true "" "plot count rabbits / 400"
"wolves" 1.0 0 -13791810 true "" "plot count wolves"
"grass / 4" 1.0 0 -10899396 true "" "if model-version = \"sheep-wolves-grass\" [ plot count grass / 4 ]"
"humans" 1.0 0 -2674135 true "" "plot count humans"

MONITOR
5
475
80
520
rabbits
count rabbits
3
1
11

MONITOR
85
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160
520
wolves
count wolves
3
1
11

MONITOR
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grass
count grass / 4
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TEXTBOX
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Rabbit settings
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TEXTBOX
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Wolf settings
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SWITCH
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show-energy?
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CHOOSER
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model-version
model-version
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1

SLIDER
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330
73
initial-number-rabbits
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73.0
1
1
NIL
HORIZONTAL

SLIDER
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80
680
113
human-gain-from-food
human-gain-from-food
0
100
13.0
1
1
NIL
HORIZONTAL

SLIDER
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120
680
153
human-reproduce
human-reproduce
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100
7.0
1
1
%
HORIZONTAL

MONITOR
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humans
count humans
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1
11

TEXTBOX
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650
33
Human settings
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0.0
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BUTTON
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243
step
go
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T
OBSERVER
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NIL
1

SLIDER
515
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shooting-accuracy
shooting-accuracy
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%
HORIZONTAL

PLOT
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Avg Age
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mean age
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100.0
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true
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"" ""
PENS
"turtles" 1.0 0 -16777216 true "" "plot mean [ age ] of turtles"
"humans" 1.0 0 -2674135 true "" "plot mean [age] of humans"
"wolves" 1.0 0 -13791810 true "" "plot mean [age] of wolves"
"rabbits" 1.0 0 -1264960 true "" "plot mean [age] of rabbits"

PLOT
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Avg Energy
tick
mean energy
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0.0
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true
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"" ""
PENS
"rabbits" 1.0 0 -1264960 true "" "plot mean [ energy ] of rabbits"
"wolves" 1.0 0 -13791810 true "" "plot mean [ energy ] of wolves"
"humans" 1.0 0 -2674135 true "" "plot mean [ energy ] of humans"
"turtles" 1.0 0 -16777216 true "" "plot mean [ energy ] of turtles"

SLIDER
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193
rabbit-lifetime
rabbit-lifetime
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ticks
HORIZONTAL

SLIDER
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505
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wolf-lifetime
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ticks
HORIZONTAL

SLIDER
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rabbit-mate-distance
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NIL
HORIZONTAL

SLIDER
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200
505
233
wolf-mate-distance
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10.0
1
1
NIL
HORIZONTAL

SLIDER
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wolf-hunt-distance
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HORIZONTAL

BUTTON
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123
Save the values
export-world user-new-file
NIL
1
T
OBSERVER
NIL
NIL
NIL
NIL
1

BUTTON
5
130
170
163
Load values
import-world user-file
NIL
1
T
OBSERVER
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NIL
NIL
NIL
1

TEXTBOX
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240
315
271
Grass settings\n
14
0.0
1

SLIDER
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160
680
193
human-lifetime
human-lifetime
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50.0
1
1
ticks
HORIZONTAL

SLIDER
515
200
680
233
human-mate-distance
human-mate-distance
0
15
2.0
1
1
NIL
HORIZONTAL

PLOT
5
300
320
470
Avg Distance Same-Breed Neighbor
ticks
mean-rdist
0.0
1.0
0.0
1.0
true
true
"" ""
PENS
"humans" 1.0 0 -2674135 true "" "plot mean [hmyclosest] of humans"
"wolves" 1.0 0 -13791810 true "" "plot mean [wmyclosest] of wolves"
"rabbits" 1.0 0 -1664597 true "" "plot mean [rmyclosest] of rabbits"

TEXTBOX
345
295
640
501
Three-Agent Predation Model: Humans, Wolves, and Rabbits \nby Alex Ismodes
35
17.0
0

@#$#@#$#@
## Overview
●Purpose and Patterns
○ The purpose of this extended wolf sheep predation model is to simulate a
simplified but realistic ecosystem and study the dynamic between its three agents which each have their respective real world movement characteristics and interactions. The original wolf sheep predation model only had two agents, each of which had characteristics which were unrealistic. For example, their movement patterns were set to random. This does not model real world sheep or wolves since they move according to stimulus, such as if they see a predator or prey. Also, their reproduction submodels were somewhat faulty since they . Additionally, the model would not function accurately with low agent set amounts (such as with only one of either or both agent sets) since the reproduction function would contribute to their unrealistic population growth. In an ecosystem, these modeled animals do not have the ability to reproduce asexually, so it does not model their interaction accurately. The model will reach an accurate level once it portrays the cyclical nature of population and energy due to predation interaction, which directly include the general measures of population number and energy.

● Entities, state variables, and scales
○ The agents that the model will have are humans, rabbits, and wolves. The
global environment will be a simplified forest. Their interactions will occur throughout the domain. The three agents’ state variables will be energy, sex, and age. Lastly, the time step will be weekly.

● Process Overview and Scheduling 
○ Foraging
-- This process essentially makes the agents search for food sources. Humans look for wolves in order to have the rabbits for themselves. The wolves look for rabbits in order to eat them. Rabbits eat the grass that is grown on the patches.
○ Predation
-- Humans and wolves kill all the other agents in a direct sense while rabbits only destroy the grass. This allows one to analyze the dynamic of competition for a common resource (rabbits) within a simulated ecosystem.

○ Reproduction
-- All three agents have the ability to reproduce as long as they are at
an equal, fixed minimum energy level or above. This process is continuous and results in being able to analyze the dynamic through changing population amounts.

## Design Concepts
● Basic Principles
○ A general concept that underlies the model’s design is that the direct and
indirect interaction among the three agents will be fair and representative of their real world interaction (in a simplified sense). The model illustrates various dynamics and patterns that result from the dynamic of humans, wolves, and rabbits in an ecosystem.

● Emergence
○ The model’s most important results and outputs are the ​population
numbers​ themselves and the ​change and patterns of the population
numbers and agents' average age​. 

● Adaptation
○ I have not thought of a way to include adaptation into the model, but I am thinking about ways in which I can include this form of behavior to all three agents

● Objectives
○ In this model, an agent’s “fitness,” that is its ability to survive and
reproduce, is used to rate decision alternatives. This ability leads the agents to make an effective survival decision, such as foraging, and it aligns with the survival concept with relation to its own spatial location and its location with regards to other variables and agents. 

● Learning
 ○ As of now, agents do not make adaptive decisions over time due to their experiences.

● Prediction
○ I am not sure how to include prediction into this model’s dynamic among
its agents. 

● Sensing
○ Agents are able to sense the proximity and agent type of nearby agents and as such will react accordingly to the stimuli with their respective characteristics. For example, if a humans senses a nearby wolf within its sensing radius then it will proceed to fire his or her gun at the wolf.

● Interaction
○ The model’s agents interact directly and indirectly. Humans and wolves
attack directly at each other and at rabbits, who only eat the grass. All agents interact with each other either through killing (not including its own agent type) or through reproduction (including its agent type).

● Stochasticity
○ I believe that the Poisson Distribution can be incorporated in the
probability of effective reproduction. This way the probability is random since there is no fixed reproduction rate. Further, there is no average reproduction rate documented for wolves and rabbit, so a random reproduction rate might be necessary instead.

● Observation
○ The ​population number,​ average age, and ​average energy by agent type​ are three outputs
that are necessary to effectively evaluate and analyze the dynamic between humans, wolves, and rabbit in this simulated ecosystem.

## Details
● Initialization
○ I will create a starting amount of 40 agents for each of the three types:
humans, wolves, and rabbit. I decided upon this amount because it is not low enough to accidentally cause premature extinction of an agent type due to variability and at the same time it is small enough to leave room for population growth.

● Input Data
○ I do not think I will have an input data in this model, but if I can properly
build it, I will attempt to add temperature/seasons to it. 

● Submodels
○ reproduce
-- This submodel is in charge of the reproduction of all the species. This submodel is effective as long as two agents are each at an equal, fixed minimum energy level or above. Further, I will attempt to incorporate the Poisson Distribution in order to simulate a random probability of reproduction. A fixed reproduction probability would be arbitrary since there is no documentation of the average rate of reproduction among wolves and rabbit.

○ kill
-- This submodel handles the different methods of killing that each
agent has, taking into account their characteristics and nature as represented by the real world. For example, humans kill using guns within a certain radius while wolves kill rabbit from up close. Essentially, the agents do not use the same kill submodel since their natural real world characteristics cause them to kill differently.

○ eat
-- This submodel handles decreasing the energy amount by an equal
fixed amount for all agent sets. It is connected to the agent’s
individual energy levels. 

○ energy
-- This submodel continuously increases the energy of all agent types since it models how one’s energy is continuously increasing (eating decreases this continuous effect).

○ hunt
-- This submodel essentially is the opposite of the flee submodel and
handles foraging. The agents use this to move towards their prey to fulfill the objective of eating it and both decreasing their energy and surviving to eventually reproduce.

○ flee
-- I’m still developing how this submodel will work, but a possibility is
to cause the agents to flee if a predator is nearby. This may also lead me to include a degree of vision for the agents to simulate how in real life one cannot see what is behind.

## CREDITS AND REFERENCES

Wilensky, U. & Reisman, K. (1998). Connected Science: Learning Biology through Constructing and Testing Computational Theories -- an Embodied Modeling Approach. International Journal of Complex Systems, M. 234, pp. 1 - 12. (The Wolf-Sheep-Predation model is a slightly extended version of the model described in the paper.)

Wilensky, U. & Reisman, K. (2006). Thinking like a Wolf, a Sheep or a Firefly: Learning Biology through Constructing and Testing Computational Theories -- an Embodied Modeling Approach. Cognition & Instruction, 24(2), pp. 171-209. http://ccl.northwestern.edu/papers/wolfsheep.pdf .

Wilensky, U., & Rand, W. (2015). An introduction to agent-based modeling: Modeling natural, social and engineered complex systems with NetLogo. Cambridge, MA: MIT Press.

Lotka, A. J. (1925). Elements of physical biology. New York: Dover.

Volterra, V. (1926, October 16). Fluctuations in the abundance of a species considered mathematically. Nature, 118, 558–560.

Gause, G. F. (1934). The struggle for existence. Baltimore: Williams & Wilkins.


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@#$#@#$#@
NetLogo 6.0.2
@#$#@#$#@
set model-version "sheep-wolves-grass"
set show-energy? false
setup
repeat 75 [ go ]
@#$#@#$#@
@#$#@#$#@
<experiments>
  <experiment name="experiment" repetitions="10" runMetricsEveryStep="false">
    <setup>setup</setup>
    <go>go</go>
    <metric>count rabbits</metric>
    <metric>count humans</metric>
    <metric>count wolves</metric>
    <metric>survivors</metric>
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    </enumeratedValueSet>
    <steppedValueSet variable="wolf-reproduce" first="5" step="2" last="15"/>
    <enumeratedValueSet variable="human-gain-from-food">
      <value value="20"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="initial-number-rabbits">
      <value value="100"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="rabbit-lifetime">
      <value value="5"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="model-version">
      <value value="&quot;rabbits-wolves-humans&quot;"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="rabbit-mate-distance">
      <value value="5"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="initial-number-humans">
      <value value="15"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="grass-regrowth-time">
      <value value="4"/>
    </enumeratedValueSet>
    <steppedValueSet variable="wolf-lifetime" first="5" step="5" last="15"/>
    <enumeratedValueSet variable="rabbit-gain-from-food">
      <value value="17"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="human-reproduce">
      <value value="2"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="rabbit-reproduce">
      <value value="40"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="wolf-mate-distance">
      <value value="10"/>
    </enumeratedValueSet>
    <enumeratedValueSet variable="shooting-accuracy">
      <value value="10"/>
    </enumeratedValueSet>
  </experiment>
</experiments>
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