BasicAggregation

turtles-own [
  stabilized?
  nearest-dist
  nearest-agent
]

; slider variables
;   num-turtles
;   ideal-dist: central ideal distance for stabilization
;   margin: how far above or below ideal-dist is acceptable for stabilization
;   velocity: how far agents move

; global variables
globals [
  stable-dist-min
  stable-dist-max
]

to setup;
  clear-all
  reset-ticks
  create-turtles num-turtles [ setxy random-xcor random-ycor ]
  set stable-dist-min ideal-dist - margin
  set stable-dist-max ideal-dist + margin
end 

to go
  ask turtles [
    maintain-dist-near
  ]
  tick
end 

to maintain-dist-near
  let nearest-group other turtles in-radius (stable-dist-max)
  set nearest-agent min-one-of nearest-group [distance myself]
  set nearest-dist distance nearest-agent
  face nearest-agent
  ifelse nearest-dist < stable-dist-min
    [ rt 180
      forward velocity ]
    [ maintain-dist-far ] ; look for faraway turtles to move closer towards (other function)
end 

to maintain-dist-far
  let nearest-group other turtles in-radius (stable-dist-max * 2)
  set nearest-agent min-one-of nearest-group [distance myself]
  set nearest-dist distance nearest-agent
  face nearest-agent
  ifelse nearest-dist > stable-dist-max
    [ forward velocity ]
    [ set stabilized? true ]
end