Fish shoals

turtles-own [enemies friends nearest_friend speed escape escapeangle alert imitation dist dist2]
globals [step]

to setup
  ;; (for this model to work with NetLogo's new plotting features,
  ;; __clear-all-and-reset-ticks should be replaced with clear-all at
  ;; the beginning of your setup procedure and reset-ticks at the end
  ;; of the procedure.)
  __clear-all-and-reset-ticks
  ask patches [set pcolor 101 + random-normal 0 0.1]
   cro predators_num [setxy random-xcor random-ycor set color red set shape "mare" set size 2.3 set speed random-float 0.5 ]
  cro fish_num
  [setxy random-xcor random-ycor
   set shape "mare"
   set color gray
   set size 1.3
   set speed random-float fish_speed
   set dist distance turtle 0
   set dist2 precision dist 3
   ;set label dist2
   set escape 0.3
   set escapeangle random-float 50
   set imitation (speed + escape) - speed]
set step random 1 + 3
end 

to go
choose_step
ask turtles [if speed < 0.1 [set speed 0]]
repeat step [ask turtles [fd speed] display]
ask turtles with [size = 1.3] [set color gray set speed random-float fish_speed set escape 0.3 set dist distance turtle 0
   set dist2 precision dist 3]
plotagents
end 

to choose_step
ask turtles with [size = 1.3]; chiedo alle turtle grigie
    [find_enemies ; trovate nemici
     ifelse any? enemies ; SE CI SONO NEMICI
        [set heading heading + 70 set speed speed + escape set color white] ; impostate in base a questi parametri l'orientamento ed il passo
        [find_friends ; SE NON CI SONO NEMICI... TROVA AMICI
        ifelse any? friends ; SE CI SONO AMICI...
           [find_nearest_friend  ; trova l'amico pi� vicino
            let heada [heading] of nearest_friend ; leggi il suo orientamento
            let speeda [speed] of nearest_friend ; leggi la sua velocita
            let colora [color] of nearest_friend
            set imitation (fish_speed + escape) - speeda
            ifelse eastwest?
                 [set heading heada + random-float (fish_speed + escape) - speeda ]
                 [set heading heada - random-float (fish_speed + escape) - speeda ]
            set color colora
           ]
                                                      ; ALTRIMENTI, SE NON CI SONO AMICI
          [ifelse eastwest?
          [set heading heading + random-float 15 ]
          [set heading heading - random-float 15]]
          ]
        ]

ask turtles with [color = red] ; chiedo alle turtle rosse
[set heading heading + random-normal 0 20 set speed random-float 0.3]
end 

to-report eastwest?  ; restituisce vero/falso in base al parametro [p] che viene "passato" nella procedura che richiama "to-report probability-fn?
  ifelse (random-float 100) < 50 ; se un numero a caso tra 0 e 1 � minore di p allora restituisci vero, altrimenti restitutisci falso
    [report true];
    [report false]
end 

to find_enemies
 set enemies other turtles in-cone visual_depth visual_angle with [color = red]
end 

to find_friends
 set friends other turtles in-cone visual_depth 180 with [color = gray]
end 

to find_nearest_friend;; turtle procedure
  set nearest_friend min-one-of friends [distance myself]
end 

to plotagents
set-current-plot "mean distance graph"
  set-current-plot-pen "Meandist"
    plot (mean [dist2] of turtles)
end