Simple implementation of the El Farol Bar Problem

to setup
  ca
  set-default-shape turtles "person"
  ask patches with [abs pxcor < 5 and abs pycor < 4] [set pcolor white]
  ask n-of n-of-agents patches with [pcolor = black] [sprout 1]
  reset-ticks
end 

to go
  choose
  tick
end 

to choose
  let turtles-in-the-bar count turtles-on patches with [pcolor = white]
  ask n-of round (n-of-agents * simultaneous-move-prop) turtles [
    ifelse turtles-in-the-bar > bar-limit
    [
      move-to one-of patches with [pcolor = black]
    ]
    [
      move-to one-of patches with [pcolor = white]
    ]
  ]
end