Flibs'NFarol

;;  _________________________________________________________________________________________________________________
;;
;;  --------------------   FlibsN'Farol   ---------------------------------------------------------   FlibsN'Farol
;;  FlibsN'Farol   ---------------------------------------------------------   FlibsN'Farol   -----------------------
;;  _________________________________________________________________________________________________________________



breed     [flibs flib]     ;; FLiBs (finite livig blobs) are the agents of the model: they are structured as
                           ;; finite automata. They have "a finite number of states; an input signal
                           ;; causes it to change automatically from one state to another. The kind of automaton
                           ;; used in a flib also generates signals. Incoming and outgoing signals are represented
                           ;; within the automaton by symbols. When a signal is reiceved, the automaton changes
                           ;; state and emits a second signal" (A. K. Dewdney)


flibs-own [chromosome      ;; every flib owns a chromosome, that is a string codifying its state transitions schema
           chrom-10        ;; the corresponding decimal number of a binary chomosome string (when the flibs possible
                           ;; states are less than three)
           state           ;; the current inner state of the flib
           choice          ;; choice/prevision expressed by the flib regarding to go or not to go to the bar
           fitness         ;; a measure of flibs' prevision ability to forestall if the bar will be crowded or not
           ]


globals  [tot_attend        ;; total of attendances during one season to "El Farol" bar (i.e. 100 cycles)
          sigma_attend      ;; an accumulator for the previous variable
          crowded           ;; a switch recording the state of the bar: 1 if overcrowded, 0 if not
          lorenz-points     ;; list of the Lorenz curve ordinates
          gini-index-reserve;;
          sigma-gini        ;; an accumulator for the previous variable
          diversity         ;; the different chromosomes number in the flibs population
          best              ;; the best flibs fitness value
          worst             ;; the worst flibs fitness value
          donor             ;; one of best performing flibs sharing part of its genes
          recipient         ;; one flib acquiring genes from the donor flib
          a-split           ;; the first cut in the recipient's chromosome
          b-split           ;; the second cut in the recipient's chromosome
          locus             ;; pointer/counter of chromosome loci
          ]



;;  ----------   SETUP PROCEDURES   ----------------------------------------------------------------------------------
;;  ------------------------------------------------------------------------------------------------------------------

to setup           ;; initializing the model
  clear-all
  ;; create the bar area (green) and an elsewhere (blue)
  ask patches  [set pcolor blue]
  ask patches with [abs pxcor < 10 and abs pycor < 7] [set pcolor green]
  ask patches with [pxcor = 9 and pycor = 7] [set plabel ["El Farol Bar"]]
  ask patches with [pxcor = 21 and pycor = -21] [set plabel ["Somewhere else"]]

  ;; flibs and their chromosomes are generated
  ask n-of num-flibs patches [sprout-flibs 1 [
    set shape "flib"
    set color white
    set size 2
    set chromosome ""
    set state random num-states]
  ]
  set locus 0
  ask flibs [chromosome-genesis]
  if num-states > 2 [notice]
  reset-ticks
end 

to chromosome-genesis   ;; Chromosomes are strings randomly built through an iterative procedure.
                        ;; The content of even string's positions are 1 or 0: they are the
                        ;; flibs outgoing signals representing respectively the intention to go or not to go
                        ;; to the bar. Odd string's positions represent a possible flib's states.
  set chromosome word chromosome (word (random 2) (random num-states))
  set locus locus + 1
  if locus < num-states * 2 [chromosome-genesis]
  set locus 0
end 

to notice
  output-print "Sequences separation takes"
  output-print "place for binary chromosomes"
  output-print "only. The analysis is"
  output-print "unavailable when the number"
  output-print "of flibs' states are higher"
  output-print "than two."
end 



;;  ----------   RUNTIME PROCEDURES   --------------------------------------------------------------------------------
;;  ------------------------------------------------------------------------------------------------------------------

to go
  set tot_attend 0
  ask flibs [set fitness 0 set state 0]

  repeat 100 [el-farol] ;; a 100 cycles tournement will correspond to a season to "El Farol" bar (i.e. 100 nights)

  if sum [fitness] of flibs = 0 [  ;; no fitness no progress
    show "fitness null for every flibs"
    stop
  ]
  analyse   ;; some relevant "El Farol" seasonal results are picked and processed

  ;; after every season, one breeding and one mutational event can occur
  if random-float 1 < mate-rate [conjugation]
  if random-float 1 < mutation-rate [ask one-of flibs [mutate]
  ]
  tick
end 


;; Operator 1: A NIGHT TO EL FAROL BAR
;; -------------------------------------------------------------------------------------------------------------------

to el-farol
  let attendance 0    ;; the variable records the fraction of agents attending the bar during one night
  flibs-behaviour
  ;; bar attendance is the result of every flibs choices
  set attendance sum [choice] of flibs / num-flibs
  set tot_attend tot_attend + attendance
  ;; comparing the attendance and the threshold value, the (over)crowded state of the bar is determined
  if attendance >= threshold [set crowded 1
    ;; if the bar is crowded, who have chosen to stay elsewhere are rewarded
    ask flibs with [choice = 0] [set fitness fitness + 1] ]
  if attendance < threshold [set crowded 0
    ;; if the bar is not crowded, who have chosen to go there are rewarded
    ask flibs with [choice = 1] [set fitness fitness + 1] ]
end 

to flibs-behaviour
  ask flibs [
    ;; the flibs state is updated
    set state read-from-string item (4 * state + 2 * crowded + 1) chromosome
    ;; each flib processes its choice (to go or not to go)
    set choice read-from-string item (4 * state + 2 * crowded) chromosome
    ;; flibs behaviour is displayed
    ifelse choice = 0
      [move-to one-of patches with [pcolor = blue]]
    [move-to one-of patches with [pcolor = green]]
  ]
end 

to analyse
  set best max [fitness] of flibs
  set worst min [fitness] of flibs
  ask flibs [set color scale-color red fitness 101 0 set label fitness]
  set sigma_attend sigma_attend + tot_attend / 100
  update-lorenz-and-gini
  diversity-assesment
  if num-states < 3 [chrom-analysis]
end 

to update-lorenz-and-gini
  let sorted-comfort sort [fitness] of flibs
  let total-comfort sum sorted-comfort
  let comfort-sum-so-far 0
  let index 0
  set gini-index-reserve 0
  set lorenz-points []
  repeat num-flibs [
    set comfort-sum-so-far (comfort-sum-so-far + item index sorted-comfort)
    set lorenz-points lput ((comfort-sum-so-far / total-comfort) * 100) lorenz-points
    set index (index + 1)
    set gini-index-reserve
      gini-index-reserve +
      (index / num-flibs) -
      (comfort-sum-so-far / total-comfort)
  ]
    set sigma-gini sigma-gini + ((gini-index-reserve / num-flibs) * 2)
end 

to diversity-assesment
  let sort-chrom sort [chromosome] of flibs
  let index 1
  set diversity 1
  repeat num-flibs - 1 [
    if item index sort-chrom != item (index - 1) sort-chrom [set diversity diversity + 1]
    set index (index + 1)
  ]
end 

to chrom-analysis
  output-print ""
  output-print ""
  output-type word "------ season " ticks
  output-print " ------------"
  output-print ""
  ask flibs [set chrom-10 0]
  binary2decimal
  if num-states = 1 [output-print " id.  bindec   fitness"]
  if num-states = 2 [output-print " id.  bin  dec  fitness"]
end 

to binary2decimal
  ask flibs
    [set chrom-10 chrom-10 + (read-from-string item locus reverse chromosome) * 2 ^ locus]
  set locus locus + 1
  ifelse locus < num-states * 4 [binary2decimal]
    [set locus 0
     ask flibs [ifelse who <= 9 [output-type word "00" who]
        [ifelse who <= 99 [output-type word "0" who]
          [output-type who]
        ]
      output-type word "   " chromosome
      ifelse chrom-10 < 10 [output-type word "       " chrom-10]
        [ifelse chrom-10 < 100 [output-type word "      " chrom-10]
          [output-type word "     " chrom-10]
      ]
    output-print word "   " fitness]
  ]
  set locus 0
end 



;; Operator 2: GENETIC SHUFFLING
;; -------------------------------------------------------------------------------------------------------------------

to conjugation
  ;; the conjugation process requires two flibs' chromosomes: the donor and the recipient:
  ;; just the second one undergoes to hybridization
  select-flibs
  ask flib recipient [genetic-shuffling]
end 

to select-flibs
  ;; there are three selection modes to choose the "donor" and "recipient" chromosomes: they can be the fittest,
  ;; the misfittest, or they can be randomly chosen
  if donor-selection = "random"     [set donor [who] of one-of flibs]
  if donor-selection = "fittest"    [set donor [who] of one-of flibs with [fitness = best]]
  if donor-selection = "misfittest" [set donor [who] of one-of flibs with [fitness = worst]]
  if recipient-selection = "random"     [set recipient [who] of one-of flibs]
  if recipient-selection = "fittest"    [set recipient [who] of one-of flibs with [fitness = best]]
  if recipient-selection = "misfittest" [set recipient [who] of one-of flibs with [fitness = worst]]
  ;; self conjugation is forbidden
  if donor = recipient [select-flibs]
end 

to genetic-shuffling
  ;; a genes sequence included between a-split and b-split restriction sites is randomly choosen
  set a-split random (num-states * 4)
  set b-split random (num-states * 4)
  set locus 0
  hybridization
  set fitness 0
end 

to hybridization
 ;; the genes' sequence included between a-split and b-split restriction sites on a random
 ;; flib is replaced by the corresponding sequence on one of the most performing flibs;
 ;; chromosomes are treated as circular
 if a-split < b-split [
    set chromosome replace-item (a-split + locus)
      chromosome (item (a-split + locus) [chromosome] of flib donor)
    set locus (locus + 1) if locus < b-split - a-split
      [hybridization]
  ]
 if a-split > b-split [
    set chromosome replace-item ((a-split + locus) mod (num-states * 4))
      chromosome (item ((a-split + locus) mod (num-states * 4)) [chromosome] of flib donor)
    set locus (locus + 1) if locus < (num-states * 4) - (a-split - b-split)
      [hybridization]
  ]
  set locus 0
end 


;; Operator 3: MUTAGENESIS
;; -------------------------------------------------------------------------------------------------------------------

to mutate
  ;; mutations occur randomly at a given frequency on one locus only
  let dice random length chromosome
  let muton read-from-string item dice chromosome
  ifelse dice mod 2 = 0
    [set chromosome replace-item dice chromosome word ((muton + 1) mod 2) ""]
  [set chromosome replace-item dice chromosome word ((muton + 1) mod num-states) ""]
  set fitness 0
end 




; Copyright 2022 Cosimo Leuci.
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