Evolution of Aggression

;; Hawks, doves and retaliators are breeds of turtle.
breed [hawks hawk]  
breed [doves dove] 
breed [retaliators retaliator]
;; Hawks, doves and retaliators have a fitness, a reproduction time and an engaged flag 
turtles-own [fitness reproduction-time engaged ]       

;; Initialisation of the system

to setup

  ;; Remove all previous turtles
  ;; (for this model to work with NetLogo's new plotting features,
  ;; __clear-all-and-reset-ticks should be replaced with clear-all at
  ;; the beginning of your setup procedure and reset-ticks at the end
  ;; of the procedure.)
  __clear-all-and-reset-ticks

  ;; Create doves and initialise their variables
  set-default-shape doves "default"
  create-doves initial-number-doves    [
    ;; Doves are blue
    set color blue
    ;; Labels are white
    set label-color white
    ;; The fitness is set to the intial value
    set fitness initial-fitness
    ;; The reproduction time is generated according to a normal distribution
    set reproduction-time round (random-normal time-to-reproduce (time-to-reproduce / 5))
    ;; Initially each dove is not engaged in a fight
    set engaged 0
    ;; Located at random position
    setxy random-xcor random-ycor
  ]

  ;; Create hawks and initialise their variables
  set-default-shape hawks "default"
  create-hawks initial-number-hawks  
  [
    ;; Hawks are red
    set color red
    ;; Labels are white
    set label-color white
    ;; The fitness is set to the intial value
    set fitness initial-fitness
    ;; The reproduction time is generated according to a normal distribution
    set reproduction-time round (random-normal time-to-reproduce (time-to-reproduce / 5))
    ;; Initially each hawk is not engaged in a fight
    set engaged 0
    ;; Located at random position
    setxy random-xcor random-ycor
  ]
  
  ;; Create retaliators and initialise their variables
  set-default-shape retaliators "default"
  create-retaliators initial-number-retaliators 
  [
    ;; Retaliators are green
    set color green
    ;; Labels are white
    set label-color white
    ;; The fitness is set to the intial value
    set fitness initial-fitness
    ;; The reproduction time is generated according to a normal distribution
    set reproduction-time round (random-normal time-to-reproduce (time-to-reproduce / 5))
    ;; Initially each retaliator is not engaged in a fight
    set engaged 0
    ;; Located at random position
    setxy random-xcor random-ycor
  ]
  
  display-labels

  update-plot
end 

to go

  ;; simulation stops if there are no turtles  
  if not any? turtles [ stop ]

  ;; All breeds move, decrease their time to reproduction, fight,
  ;; set their engaged flag to 0, die and reproduce
  ask doves [
    move
    set reproduction-time reproduction-time - 1
    fight-as-dove
    set engaged 0
    death
    reproduce
  ]

  ask hawks [
    move
    set reproduction-time reproduction-time - 1
    fight-as-hawk
    set engaged 0
    death
    reproduce
  ]
  
  ask retaliators [
    move
    set reproduction-time reproduction-time - 1
    fight-as-retaliator
    set engaged 0
    death
    reproduce
  ]

  ;; advance the time and update the plots 
  tick
  update-plot

  display-labels
end 

;; Procedure for all breeds

to move  
  rt (30 - (random-float 60)) ;;(random-float 180)
  fd 1 ;;2
end 

to fight-as-dove 
  ;; Only not engaged dove can start a fight
  if engaged = 0
  [
    ;; Checking if there are available opponents in the patch to
    ;; start a fight 
    let opponent one-of other turtles-here with [ engaged = 0 ]  
    if opponent != nobody   
    [
      ;;If there is a free oponent both get engaged in a fight
      set engaged 1
      ask opponent [ set engaged 1 ]
      
      ifelse is-hawk? opponent
      [ 
        ;; If opponent is a hawk, doves flee and hawks get the reward 
        ask opponent [ set fitness ([fitness] of opponent + reward) ]
      ]  
      [ 
        ;; If opponent is a dove or retaliator, doves pose for some time
        ;; which produces a penalty for wasting time. The probability of 
        ;; eventually getting the reward is 0.5     
        ifelse (random 10) < 5
        [ 
          set fitness (fitness - cost-wasted-time)
          ask opponent [ set fitness ([fitness] of opponent + reward - cost-wasted-time) ]
        ]  
        [
          set fitness (fitness + reward - cost-wasted-time) 
          ask opponent [ set fitness ([fitness] of opponent - cost-wasted-time) ]        
        ]
      ]    
      
    ]
    
  ]
end 

to fight-as-hawk
  ;; Only not engaged hawks can start a fight
  if engaged = 0 
  [ 
    ;; Checking if there are available opponents in the patch to
    ;; start a fight 
    let opponent one-of other turtles-here with [ engaged = 0 ]
    if opponent != nobody   
    [
      ;;If there is a free oponent both get engaged in a fight
      set engaged 1
      ask opponent [ set engaged 1 ]
    
      ifelse is-dove? opponent
      ;; If opponent is a dove, hawks get the reward and doves flee
      [
        set fitness (fitness + reward) 
      ]    
      ;; If opponent is a hawk or a retaliator, they fight until one of them gets seriously injured 
      [ 
        ifelse (random 10) < 5
        [ 
          set fitness (fitness - cost-injure)
          ask opponent [ set fitness ([fitness] of opponent + reward) ]
        ]  
        [
          set fitness (fitness + reward)
          ask opponent [ set fitness ([fitness] of opponent - cost-injure) ]        
        ]
      ]  
      
    ]
  ]
end 

to fight-as-retaliator 
  ;; Only not engaged retaliators can start a fight
  if engaged = 0
  [
    ;; Checking if there are available opponents in the patch to
    ;; start a fight 
    let opponent one-of other turtles-here with [ engaged = 0 ]
     if opponent != nobody   
    [
      ;;If there is a free oponent both get engaged in a fight
      set engaged 1
      ask opponent [ set engaged 1 ]

      ifelse is-hawk? opponent
      ;; Retaliator behaves as a hawk against a hawk
      [          
        ifelse (random 10) < 5
        [ 
          set fitness (fitness - cost-injure)
          ask opponent [ set fitness ([fitness] of opponent + reward) ]
        ]  
        [
          set fitness (fitness + reward)
          ask opponent [ set fitness ([fitness] of opponent - cost-injure) ]        
        ]
      ]
      ;; Retaliator behaves as a dove agains another retaliator or a dove        
      [       
        ifelse (random 10) < 5
        [ 
          set fitness (fitness - cost-wasted-time)
          ask opponent [ set fitness ([fitness] of opponent + reward - cost-wasted-time) ]
        ]  
        [
          set fitness (fitness + reward - cost-wasted-time) 
          ask opponent [ set fitness ([fitness] of opponent - cost-wasted-time) ]        
        ]
      ]    
      
    ]
  ]
end 

to reproduce  ;; turtle procedure
  ;; when reproduction time equals zero breeds reproduce
  if reproduction-time = 0 [
      hatch 2 [  
        rt random-float 360 fd 2 
        set fitness initial-fitness
        set reproduction-time round (random-normal time-to-reproduce (time-to-reproduce / 5))
    ]
    die
  ]
end 

to death  ;; turtle procedure
   ;when fitness dips below zero, die
  if fitness < 0 [ die ]
end 

to update-plot
  set-current-plot "populations"
  set-current-plot-pen "doves"
  plot count doves
  set-current-plot-pen "hawks"
  plot count hawks
  set-current-plot-pen "retaliators"
  plot count retaliators
  set-current-plot "fitness"
  set-current-plot-pen "dove-fitness"
  if any? doves [
    plot mean [fitness] of doves ]
  set-current-plot-pen "hawk-fitness"
  if any? hawks [
    plot mean [fitness] of hawks ]
  set-current-plot-pen "retaliator-fitness"
  if any? retaliators [
    plot mean [fitness] of retaliators ]
  set-current-plot-pen "average-fitness"
  plot mean [fitness] of turtles 
  set-current-plot "ratio"
  set-current-plot-pen "doves"
  if any? turtles [
   plot count doves / count turtles 
  ]
  set-current-plot-pen "hawks"
  if any? turtles [
   plot count hawks / count turtles 
  ]
  set-current-plot-pen "retaliators"
  if any? turtles [
   plot count retaliators / count turtles 
  ]
end 

to display-labels
  ask turtles [ set label "" ]
  if show-fitness? [
    ask hawks [ set label fitness ]
    ask doves [ set label fitness ]
    ask retaliators [ set label fitness ]
  ]
end 


; Copyright 2011 Francisco J. Romero-Campero.
; http://www.cs.us.es/~fran/