Population Dynamics

patches-own [food]

turtles-own [
 gender ;;  male or female
 married?  ;; the maritial status of the agent
 spouse  ;; the spouse of the agent if it is married
 age ;; the age of agent with maximum of 100
 vehicle? ;; it is true if the agent has a wehicle and false if the agent has no vehicle
 parasite? ;; when the population exceeds the critical threshold, 0.1 of them get infected with parasite
 energy  ;; the energy of the agent
]
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;setup block

to setup
  ca
  random-seed my-seed

  ask patches [
    set food random 10
    recolor-patch
  ]
  crt initial-pop [
    initial-properties
    setxy random-xcor random-ycor
  ]

  reset-ticks
end 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; Go block

to go
  if not any? turtles [stop]
  if ticks = stop-time [stop]

ask turtles [
    update-age
    eat
  ]


ask turtles with [ age >= 18 and not married? ] [
    move
    evaluation-for-marriage ;; it assess the other agents on  when it can marry or not
  ]

ask turtles with [ married? ] [
    reproduction
  ]

death-by-energy-loss ;; death by loss of energy
unexpected-events  ;;  unexpcted events like car accidents, airplane crashes
unexpected-illness ;; unexpcted illnesses like cancers, HIV and parasite spreading



ask turtles with [parasite?] [set age age + random 4 ]


ask patches [ regrowth  recolor-patch ]



  tick
end 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; helper procedures
;;;;;;;;;;;;;;;;;;a patch-procedure

to recolor-patch
  set pcolor scale-color green food 10 0
end 
;;;;;;;;;;;;;;;;;; a turtle-procedure

to initial-properties
set size 2
set color magenta
set spouse nobody
set married? false
set age 0
set parasite? false
set energy 100
ifelse random-float 1.0 <= percentage-of-vehicle-owners [ set vehicle? true] [set vehicle? false]
ifelse random-float 1.0 <= 0.5 [set gender "male" set shape "person"] [ set gender "female" set shape "woman"]
end 
;;;;;;;;;;;;;;;;;; a turtles procedure

to update-age
  if ticks mod ticks-as-a-year = 0 [set age age + 1 ]
  if age >= 100 [ get-dead ]
end 

to get-dead
if spouse != nobody [ask spouse [ set spouse nobody set married? false ] ]
die
end 

;;;;;;;;;;;;;;;;;;a turtle procedure

to eat
  let target one-of patches with [food >= 1]
  set energy energy - energy-lost-for-finding-food
  if target != nobody [
    ask target [ set food food - 1 ]
    set energy energy + energy-gained-from-eating
  ]
end 
;;;;;;;;;;;;;;;;;;;;;;a turtle procedure

to move
  rt random-float 90
 lt random-float 90
  if not can-move? 1 [ rt 180]
  fd 0.75
  set energy energy - energy-lost-from-moving
end 
;;;;;;;;;;;;;;;;;;;;;; turtle procedure of marriage mechanisms

to evaluation-for-marriage
  let marriage-target one-of other turtles-here with [gender != [gender] of myself]  ;; target for marriage

  if  marriage-target != nobody and [age] of marriage-target >= 18 [

  let hypothesis? [married?] of marriage-target = true ;; a hypothesis that the target is married

    ifelse hypothesis? [ move ] [ marry marriage-target]

  ]
end 

to marry [person]
   set married? true set spouse person set-color
   ask person [set married? true set spouse myself set-color ]
end 

to set-color
  set color ifelse-value (gender = "male") [blue] [orange] ;; married man & woman
end 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;a turtle procedure

to reproduction
  if  gender = "female" and married? and age >= min-age-of-reproduction and age <= max-age-of-reproduction [
    if random-float 1.0 <= probability-of-childbearing [set energy energy - 20 hatch 1 [
    initial-properties

  ]  ]   ]
end 
;;;;;;;;;;;;;;;;;;;;;;;;;;; trurtle procedures for death by energy loss, unexpcted events and unexpected illness

to death-by-energy-loss
  ask turtles [ if energy <= 0 [ get-dead]  ]
end 

to unexpected-events
  ;; for car accident
  ask turtles [if age >= 18 and vehicle?
                      [ if possibility-of-vehicle-accident?
                                      [ ifelse high-speed-crash?  [ if random-float 1.0 <= 0.8 [get-dead]]   [if random-float 1.0 <= 0.1 [get-dead] ]  ] ] ]
end 

to unexpected-illness
  ;; for parasite spread
  if count turtles >= critical-threshold [ ask n-of (0.05 * count turtles) turtles [ set parasite? true] ]
end 

;;;;;;;;;;;;;;;;;;;;;;;;;; a trurtle procedure

to regrowth
  if random-float 1.0 <= probability-of-regrowth [ if food <= 1 [set food food + random 10] ]
end 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; reporters

to-report married-people
  report count turtles with [ married?]
end 

to-report single-people
  report count turtles with [not married?]
end 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; shocks

to shock-for-single-agents  ;; unmaried agents
  ask turtles with [ not married? ] [ move-to one-of patches]
end 

to shock-for-all-agents
  ask turtles  [ move-to one-of patches]
end 

;;;;;;;;;;; The voluem of food

to-report north-east
  report sum [food] of patches with [ pxcor > 0 and pycor > 0 ]
end 

to-report north-west
  report sum [food] of patches with [ pxcor < 0 and pycor > 0 ]
end 

to-report south-east
  report sum [food] of patches with [ pxcor > 0 and pycor < 0 ]
end 

to-report south-west
  report sum [food] of patches with [ pxcor < 0 and pycor < 0 ]
end