To Mask or Not to Mask

;; To Mask or Not to Mask - NetLogo Code
;; David Knoke, University of Minnesota
;; May 30, 2023
;;
;; Use slider to set population size between 1,000 and 3,000 in increments of 500
;; Use sliders to set percents of population Republican & Democrat mask-wearers and unmasked
;; Based on Gallup and Pew Polls in June 2020:
;; Proportions of partisans:  Democrat = .56    Republican = .44
;; Proportions wearing masks: Democrat = .43    Republican = .23
;; Proportions not masked:    Democrat = .13    Republican = .21

breed [repms repm]
breed [repns repn]
breed [demms demm]
breed [demns demn]

globals [
  colors   ;; Republican Masked = red, Republican Not Masked = pink, Democrat Masked = blue, Democrat Not Masked = cyan
  initial-red    ;; How many turtles red at start?
  initial-blue   ;; How many turtles blue at start?
  initial-pink   ;; How many turtles pink at start?
  initial-cyan   ;; How many turtles cyan at start?
  infectedreps
  infecteddems
  ratiorepsdems
  infectedmaskedreps
  infectedmaskeddems
  infectedunmaskedreps
  infectedunmaskeddems
]

to setup
  clear-all
  ask patches [set pcolor white]    ;; Make all patches white

  create-repms ((Population_Size) * (%_Republicans_Masked / 100))  [  ;; create initial Number of Republicans Wearing Masks
    setxy random-xcor random-ycor
    set color red
    set shape "person"
    set size 2
  ]
  create-repns ((Population_Size) * (%_Republicans_Unmasked / 100))  [  ;; create initial Number of Republicans Not Wearing Masks
    setxy random-xcor random-ycor
    set color pink
    set shape "person"
    set size 2
  ]
  create-demms ((Population_Size) * (%_Democrats_Masked / 100))  [  ;; create initial Number of Democrats Wearing Masks
    setxy random-xcor random-ycor
    set color blue
    set shape "person"
    set size 2
  ]
  create-demns ((Population_Size) * (%_Democrats_Unmasked / 100))   [  ;; create initial Number of Democrats Not Wearing Masks
    setxy random-xcor random-ycor
    set color cyan
    set shape "person"
    set size 2
  ]
  ask n-of (Population_Size * .01) turtles [set color black    ;; Initial infected turtles are 1% of population
  ]
  ;;  Count how many turtles of each color at start
  set initial-red count turtles with [color = red]
  set initial-blue count turtles with [color = blue]
  set initial-pink count turtles with [color = pink]
  set initial-cyan count turtles with [color = cyan]
  reset-ticks
end 

to go
  ;; Stop the simulation when no turtles remain infected (black)
  if (count turtles with [color = black] = 0)
  [stop]
  move
  infect1
  infect2
  removal
  tally
  tick
end 

to move
  ;; Turtles move one patch in a randomly selected 360-degree direction; removed turtles do not move
  ask turtles with [color != green][
    right random 360
    forward 1
  ]
end 

to infect1
  ;; Republicans encountering an infected agent become infected if a random number is less than the infection rate for the masked or the unmasked
  ask turtles with [color = red] [
    if any? turtles-here with [color = black] and random 100 < Masked_Infectiousness [
      set color black]
  ask turtles with [color = pink] [
    if any? turtles-here with [color = black] and random 100 < Unmasked_Infectiousness [
      set color black]
    ]
  ]
end 

to infect2
  ;; Democrats encountering an infected agent become infected if a random number is less than the infection rate for masked or not masked
  ask turtles with [color = blue] [
    if any? turtles-here with [color = black] and random 100 < Masked_Infectiousness [
      set color black]
  ask turtles with [color = cyan] [
    if any? turtles-here with [color = black] and random 100 < Unmasked_Infectiousness [
      set color black]
    ]
  ]
end 

to removal
  ;; Infected persons (black) are removed (turn green & stop infecting others) if a random number from 1 to 100 is below the removal rate (1 to 10)
  ask turtles with [color = black] [
    if random 100 < Removal_Rate [
      set color green]
  ]
end 

to tally  ;; Percentages for BehaviorSpace, based on Population_Size
  set infectedreps (100 - (((count turtles  with [color = red]) + (count turtles with [color = pink])) / (initial-red + initial-pink) * 100))
  set infecteddems (100 - (((count turtles  with [color = blue]) + (count turtles with [color = cyan])) / (initial-blue + initial-cyan) * 100))
  ;; Add +1 to denominator to avoid division by zero:
  set ratiorepsdems (infectedreps / (infecteddems + 1))
  set infectedmaskedreps (100 - (count turtles with [color = red] / initial-red * 100))
  set infectedmaskeddems (100 - (count turtles with [color = blue] / initial-blue * 100))
  set infectedunmaskedreps (100 - (count turtles with [color = pink] / initial-pink * 100))
  set infectedunmaskeddems (100 - (count turtles with [color = cyan] / initial-cyan * 100))
end