Parrondo on a network

;;
;; internal variables for agents
;;
turtles-own [
  state   ;; current state, 1 - winning, 0 - loosing
  state-1 ;; state in the previous round, 1 - winning, 0 - loosing
  wealth  ;; total wealth, set to some initial value during the setup
]

;;
;; setup the world: creat agents, assign states
;;

to setup
  clear-all
  ask patches [
    set pcolor white
    sprout 1 [
      set wealth intial-wealth
      set shape "person"
      ifelse random-float 1 < 0.5 [
        set state 1
      ][
        set state 0
      ]
      ifelse random-float 1 < 0.5 [
        set state-1 1
      ][
        set state-1 0
      ]
    ]

  ]
  reset-ticks
end 

;;
;; main process
;;

to go
  ask one-of turtles [

    ;; position swapping process
    if random-float 1.0 > swap-prob [
      swap-postions
    ]

    ;; include more colors and id
    show-debug-info

    ;;
    ;; main switch based on the type of selected game
    ;;
    ifelse random-float 1.0 < gameA-prob [
      zero-sum-game ;; game A
    ][
      (
        ifelse gameB-type = "capital-based" [
          capital-based-game
        ] gameB-type = "niche-based" [
          niche-based-game
        ] gameB-type = "state-based" [
          state-based-game
        ] gameB-type = "new-type-example" [
          new-type-game
        ]

      )

    ]
  ]
  tick
end 

;;
;; exchange postion with one of neighbours
;;

to swap-postions
  let goal one-of neighbors
  let here patch-here
  ;; migrate from the goal
  ask turtles-on goal  [
    ;;set pcolor blue
    move-to here
    show-debug-info
  ]
  ;; move to the goal
  move-to goal
end 

;;
;; display some debug information
;;

to show-debug-info
  if debug  [
    show who
    set color black
    set label who
    ifelse state = "winner" [
      set pcolor green
    ][
      set pcolor red
    ]
  ]
end 

;;
;;
;;

to warn-unimplemented
  if who = 0 [
    show "[Warning] This function is not implemented yet!"
  ]
end 

;;
;; implementation of elementary games used in the schemes
;;

;;
;; game A - zero-sum game played with probability
;;

to zero-sum-game
  ifelse random-float 1.0 < 0.5 [
    set state 1
    set wealth wealth + 1
    ask turtles-on one-of neighbors [
      set state 0
      set wealth wealth - 1
    ]
  ][
    set state 0
    set wealth wealth - 1
    ask turtles-on one-of neighbors [
      set state 1
      set wealth wealth + 1
    ]
  ]
end 

;;
;; standard verion of Parronod's scheme, based on the accumulated wealth
;;

to capital-based-game
  ;; local variable for controlling elementary game
  let pWin -1
  ;; check the condition based on divisibility and set the probability
  ifelse wealth mod bigM = 0 [
    set pWin pWinBranch1
  ][
    set pWin pWinBranch2
  ]

  ;; play with p assigned to the apropriate branch
  ifelse random-float 1.0 < pWin [
    set state 1
    set wealth wealth + 1
  ][
    set state 0
    set wealth wealth - 1
  ]
end 

;;
;;
;;

to state-based-game
  ;; set the probabilities for all cases
  let probsWinState
  (list
    pWinState00
    pWinState01
    pWinState10
    pWinState11
  )

  ;; save the current state in the history
  set state-1 state

  ;; update the state and the wealth
  ifelse ( random-float 1.0 ) < ( item (2 * state + state-1) probsWinState ) [
    set state 1
    set wealth wealth + 1
  ][
    set state 0
    set wealth wealth - 1
  ]
end 

;;
;;
;;

to niche-based-game

  ;; set the probabilities for all cases
  let probsWinNiche
  (list
    pWinNiche0
    pWinNiche1
    pWinNiche2
    pWinNiche3
    pWinNiche4
  )
  ;; read the states of agents in the von Neumann neighborhood
  let whichBranch sum [state] of turtles-on neighbors4

  ;; save the current state in the history
  set state-1 state

  ;; update the state and the wealth
  ifelse ( random-float 1.0 ) < ( item whichBranch probsWinNiche ) [
    set state 1
    set wealth wealth + 1
  ][
    set state 0
    set wealth wealth - 1
  ]
end 

;;
;; example of procedure implementing new game B
;;

to new-type-game
  warn-unimplemented
end 

;;
;;
;;

to-report mean-state
  report mean [state] of turtles
end 

;;
;;
;;

to-report mean-wealth-change
  report  ( mean [wealth] of turtles ) - intial-wealth
end 

to-report mean-wealth-change-zero
  report  ( [wealth] of turtle 0 ) - intial-wealth
end