;; SUMMARY
;;;;  A NetLogo model.
;; COPYRIGHT & LICENSE
;;;; Copyright © 2004,2005 James P. Steiner
;;;; Some Rights Reserved.
;;;; Creative Commons Attribution-NonCommercial-ShareAlike License v. 2.0.
;;;; Visit http://creativecommons.org/licenses/by-nc-sa/2.0/ for more information.
;;
breeds [ ducks]

ducks-own [ new-heading flockmates my-speed ]

to startup
   setup
end   

to setup
  ca
  create-custom-ducks population
    [ make-duck
    ]
end

to scatter ;; ducks
      setxy (random-int-or-float screen-size-x) - screen-edge-x (random-int-or-float screen-size-y) - screen-edge-y
      set heading random-int-or-float 360.0
      set new-heading heading
end

to go
  ;; the model runs faster if we don't update the screen
  ;; until after all turtles have moved
  ; no-display 
  check-pop
  ask ducks [ flock ]
  ask ducks [ move  ]
  ; display
end

to check-pop
   locals [ curr-pop ]
   set curr-pop ( count ducks )
   if curr-pop != population
   [ ifelse population > curr-pop 
     [ ;; make new ducks
       create-custom-ducks (population - curr-pop)
       [ make-duck
       ]
     ]
     [ ;; kill extra ducks 
       repeat (curr-pop - population)
       [ ask random-one-of ducks [ die ]
       ]
     ]
  ]
end

to make-duck
    set color yellow - 2 + random-int-or-float 7  ;; random shades look nice
    scatter
    set my-speed speed ; + speed * (( random 1.0) - .5)
end

to flock  ;; turtle procedure
  locals [ closest-duck
           cohere-heading
           conform-heading
           avoid-heading
           spleen-heading
           close-duck-distance
           panic
         ]
  
  set new-heading heading
  set cohere-heading heading
  set conform-heading heading
  set avoid-heading heading
  set spleen-heading heading + wheel  
  
  set flockmates visible-ducks
  
  if any? flockmates
  [
    set closest-duck duck-closest-to-me
    ;; avoid

    set close-duck-distance (distance closest-duck)
    if close-duck-distance < comfort-zone 
    [ ifelse close-duck-distance > 0
      [ set avoid-heading ( normal-360 ( 180 + towards closest-duck ) )
        set avoid-heading weighted-mean heading avoid-heading
            ( ( comfort-zone ) - close-duck-distance ) / ( comfort-zone * .5 )
      ]
      [ set avoid-heading random 360
      ]
   ]
      
    ;; cohere
    if mean-flockmates-distance > comfort-zone
    [ set cohere-heading  towards-flockmates-center ]

    ;; conform
    set conform-heading  mean-flockmates-heading
    
    set new-heading weighted-mean-multi
     spleen-heading independence
     avoid-heading  caution
     cohere-heading cohesion
     conform-heading conformity
  ]
    
end

to move
  set heading new-heading
  jump speed; my-speed
end

;;; HELPER PROCEDURES

to-report visible-ducks
  locals [ nearby-ducks]
  set nearby-ducks ducks in-radius vision-range with [self != myself]
  ifelse any? nearby-ducks
  [ report nearby-ducks with 
    [ ( vision-angle - field-of-view) < abs( subtract-headings ( heading-of myself ) ( normal-360 ( away-from myself ) ) )
        and
      ( vision-angle + field-of-view) > abs( subtract-headings ( heading-of myself ) ( normal-360 ( away-from myself ) ) )
    ]
  ]
  [ report nearby-ducks ]
  
end       

to-report duck-closest-to-me ;; turtle procedure
  report min-one-of flockmates [distance myself ]
end

to-report mean-flockmates-heading  ;; turtle procedure
  ;; We can't just average the heading variables here.
  ;; For example, the average of 1 and 359 should be 0,
  ;; not 180.  So we have to use trigonometry.
  let mean-sin mean values-from flockmates [sin heading]
  let mean-cos mean values-from flockmates [cos heading]
  ifelse mean-sin != 0 or mean-cos != 0
  [ report atan mean-sin mean-cos ]
  [ report 0 ]
end

to-report weighted-mean-multi [ ah aw bh bw ch cw dh dw ]
  ifelse (aw + bw + cw + dw) = 0
  [ report ah ]
  [ report atan ( (   (sin ah ) * aw
                    + (sin bh ) * bw 
                    + (sin ch ) * cw
                    + (sin dh ) * dw
                   ;+ (sin eh ) * ew 
                 ) / (aw + bw + cw + dw )
               )
               ( (   (cos ah ) * aw
                   + (cos bh ) * bw 
                   + (cos ch ) * cw
                   + (cos dh ) * dw
                  ;+ (cos eh ) * ew 
                 ) / (aw + bw + cw + dw )
               )
  ]
end

to-report weighted-mean [ a b c ]
    report normal-360 atan ( ( sin a + sin b ) * (  c  ) )
                           ( ( cos a + cos b ) * (1 - c) )
end
                                                
to-report towards-flockmates-center ;; turtle procedure
  ;; "towards myself" gives us the heading from the other turtle
  ;; to me, but we want the heading from me to the other turtle,
  ;; so we add 180
  report normal-360 ( atan mean values-from flockmates [sin (normal-360 (smart-towards-myself + 180 ))]
                           mean values-from flockmates [cos (normal-360 (smart-towards-myself + 180 ))] )
end

to-report mean-flockmates-distance
    report mean values-from flockmates [ distance myself ]
end

to-report smart-towards-myself
   ifelse xcor != xcor-of myself or ycor != ycor-of myself
   [ report towards myself ]
   [ report random-float 360 ]
end   
;;; PATTERN

;to pattern ;; option 1: veer to create preferred angle re nearest neighbor
;  set vee-angle subtract-headings (towards closest-duck) heading
;  set heading heading + sin( 90 + vee-angle - flock-angle )
;end      

;; ACCELLERATE      
;to accelerate
;  if speed < 1 [ set speed speed + .1 ]
;  if speed > 1 [ set speed speed - .1 ]
;end

to-report plus-or-minus-one
    report 2 * ( 0.5 - random-int-or-float 2 )
end

To-report normal-360 [ input-angle ]
; normalizes the input angle to be between 0 and 359.9999 ( 0.0 <= angle < 360.0 )
    locals [ angle ]    
      set angle input-angle
    while [ angle < 0.0 ]
      [ set angle angle + 360.0 ]
    while [ angle >= 360.0 ]
      [ set angle angle - 360.0 ]
    report angle
end

to-report away-from [ agent ]
   ifelse xcor-of agent != xcor or ycor-of agent != ycor
   [ report 180 + towards agent ]
   [ report 0 ]
end   

;; To find the difference between two headings, we can't just
;; subtract the numbers, because 0 and 360 are the same heading.
;; For example, the difference between a heading of 5 degrees
;; and a heading of 355 degrees is 10 degrees, not 350 degrees.
;;;;to-report subtract-headings [h1 h2]
;;;;  ifelse abs (h1 - h2) <= 180
;;;;    [ report h1 - h2 ]
;;;;    [ ifelse h1 > h2
;;;;        [ report h1 - h2 - 360 ]
;;;;        [ report h1 - h2 + 360 ] ]
;;;;end
@#$#@#$#@
GRAPHICS-WINDOW
315
10
733
449
25
25
8.0
1
10
1
1
1
0
1
1
1

CC-WINDOW
5
507
742
602
Command Center
0

BUTTON
7
10
88
43
NIL
setup
NIL
1
T
OBSERVER
T
NIL

BUTTON
90
10
171
43
NIL
go
T
1
T
OBSERVER
T
NIL

SLIDER
9
77
166
110
population
population
1
200
200
1
1
NIL

SLIDER
8
265
241
298
conformity
conformity
-100
100
45
5
1
NIL

SLIDER
9
315
242
348
cohesion
cohesion
-100
100
65
5
1
NIL

SLIDER
9
364
242
397
caution
caution
-100
100
100
5
1
NIL

SLIDER
9
146
303
179
vision-range
vision-range
0
10
5.0
0.5
1
patches

SLIDER
9
111
202
144
comfort-zone
comfort-zone
0.25
5
1.0
0.25
1
patches

SLIDER
9
181
154
214
vision-angle
vision-angle
0
180
45
1
1
deg.

SLIDER
118
415
242
448
independence
independence
0
100
25
5
1
%

SLIDER
112
460
236
493
wheel
wheel
-45
45
10
1
1
NIL

BUTTON
248
450
303
483
zero
set cohesion 0\nset caution 0\nset conformity 0\nset wheel 0\nset independence .1
NIL
1
T
OBSERVER
T
NIL

SLIDER
156
181
291
214
field-of-view
field-of-view
0
90
45
1
1
+/-

BUTTON
193
12
248
45
NIL
scatter
NIL
1
T
TURTLE
T
NIL

SLIDER
9
460
111
493
speed
speed
0
5
1.0
0.1
1
NIL

BUTTON
8
215
63
248
\ | /
set vision-angle 0\nset field-of-view 45
NIL
1
T
OBSERVER
T
NIL

BUTTON
64
215
119
248
> | <
set vision-angle 90\nset field-of-view 45
NIL
1
T
OBSERVER
T
NIL

BUTTON
119
215
174
248
/ | \
set vision-angle 180\nset field-of-view 45
NIL
1
T
OBSERVER
T
NIL

BUTTON
184
215
239
248
_\ | /_
set vision-angle 45\nset field-of-view 45
NIL
1
T
OBSERVER
T
NIL

BUTTON
240
215
295
248
360
set vision-angle 90\nset field-of-view 90
NIL
1
T
OBSERVER
T
NIL

MONITOR
9
398
66
447
Total
conformity + cohesion + caution + independence
1
1

MONITOR
242
249
308
298
conf%
(word (conformity / (conformity + cohesion + caution + independence) * 100) "%")
3
1

MONITOR
243
299
308
348
cohes%
(word (cohesion / (conformity + cohesion + caution + independence) * 100) "%")
3
1

MONITOR
243
349
308
398
caut%
(word (caution / (conformity + cohesion + caution + independence) * 100) "%")
3
1

MONITOR
243
399
308
448
ind%
(word (independence / (conformity + cohesion + caution + independence) * 100) "%")
3
1

@#$#@#$#@
SUMMARY
--------------------------------------------------------------------------------
A simulation of flocking, using a slightly different technique.

WHAT IS IT?
-----------
This model is an attempt to mimic the flocking of birds, and was insprired by the Flocking Model in the NetLogo Model Library. Like the Library model, the flocks that appear in this model are not created or led in any way by special leader birds.  Rather, each bird is following exactly the same set of rules, from which apparent flocks emerge (sort-of). Unlike the library model, this model does not use discrete rules for main flocking paramaters, but rather uses a set of tendencies that steer the individuals.

The flock has several properties:

Vision Range: The distance the ducks can see. A larger vision range makes the ducks behavior more attuned to the group.

Vision Angle: The centerline of the ducks vision.
Field-of-view: The width of the ducks vision (a +/- )

Example: Vision angle 45 with field-of-view 45 means the ducks can see everything infron of themselves, out to the extreme left and right. Vision angle 0 with field-of-view 45 gives the ducks tunnel vision. The pre-set vision angle buttons provide a sample of likely vision arrangements

These settings control a ducks awareness of other ducks. These are called "flockmates"

Comfort-zone: If a duck can see another duck within it's comfort-zone, its tendancy to avoid increases.

Conformity:
-----------
This defines tendency of a duck to align with its flockmates.
  100 - strongly tends to align
    0 - never aligns
 -100 - strongly tends to go the opposite way

Cohesion:
---------
This defines tendency of a duck to move closer to the center of its flock mates.
  100 - strongly tends to move toward center
    0 - never moves toward center
 -100 - strongly tends to move away from center

Caution:
--------
This defines tendency of a duck to move away from ducks that get within the comfort-zone.
  100 - strongly moves away
    0 - never moves away

Independence:
~~~~~~~~~~~~~
This defines tendency of a duck to maintain its own heading.
  100 - strongly independent
    0 - not at all independent

Wheel:
~~~~~~
The defines the amount that a duck will change direction, it is tied to independence, so a strongly independent duck with a large wheel will turn frequently.

Speed:
~~~~~~
The size of the step the birds take. Note that wierd things happen when speed is greater then comfort-zone, or near each other.

COPYRIGHT
--------------------------------------------------------------------------------
Copyright © 2004, 2005 James P. Steiner.

LICENSE
--------------------------------------------------------------------------------
Creative Commons Attribution-NonCommercial-ShareAlike License v. 2.0.
Visit http://creativecommons.org/licenses/by-nc-sa/2.0/ for more information.

DISCLAMER
--------------------------------------------------------------------------------
THIS SOFTWARE HAS BUGS.
No warrenties of any kind are provided for this software.
By using this software, you agree to indemnify the author for any damages arising from or related to your use of the software, or your provision of the software to others for use.
@#$#@#$#@
default
true
0
Polygon -7500403 true true 150 5 40 250 150 205 260 250

ant
true
0
Polygon -7500403 true true 136 61 129 46 144 30 119 45 124 60 114 82 97 37 132 10 93 36 111 84 127 105 172 105 189 84 208 35 171 11 202 35 204 37 186 82 177 60 180 44 159 32 170 44 165 60
Polygon -7500403 true true 150 95 135 103 139 117 125 149 137 180 135 196 150 204 166 195 161 180 174 150 158 116 164 102
Polygon -7500403 true true 149 186 128 197 114 232 134 270 149 282 166 270 185 232 171 195 149 186
Polygon -7500403 true true 225 66 230 107 159 122 161 127 234 111 236 106
Polygon -7500403 true true 78 58 99 116 139 123 137 128 95 119
Polygon -7500403 true true 48 103 90 147 129 147 130 151 86 151
Polygon -7500403 true true 65 224 92 171 134 160 135 164 95 175
Polygon -7500403 true true 235 222 210 170 163 162 161 166 208 174
Polygon -7500403 true true 249 107 211 147 168 147 168 150 213 150

arrow
true
0
Polygon -7500403 true true 150 0 0 150 105 150 105 293 195 293 195 150 300 150

bee
true
0
Polygon -1184463 true false 151 152 137 77 105 67 89 67 66 74 48 85 36 100 24 116 14 134 0 151 15 167 22 182 40 206 58 220 82 226 105 226 134 222
Polygon -16777216 true false 151 150 149 128 149 114 155 98 178 80 197 80 217 81 233 95 242 117 246 141 247 151 245 177 234 195 218 207 206 211 184 211 161 204 151 189 148 171
Polygon -7500403 true true 246 151 241 119 240 96 250 81 261 78 275 87 282 103 277 115 287 121 299 150 286 180 277 189 283 197 281 210 270 222 256 222 243 212 242 192
Polygon -16777216 true false 115 70 129 74 128 223 114 224
Polygon -16777216 true false 89 67 74 71 74 224 89 225 89 67
Polygon -16777216 true false 43 91 31 106 31 195 45 211
Line -1 false 200 144 213 70
Line -1 false 213 70 213 45
Line -1 false 214 45 203 26
Line -1 false 204 26 185 22
Line -1 false 185 22 170 25
Line -1 false 169 26 159 37
Line -1 false 159 37 156 55
Line -1 false 157 55 199 143
Line -1 false 200 141 162 227
Line -1 false 162 227 163 241
Line -1 false 163 241 171 249
Line -1 false 171 249 190 254
Line -1 false 192 253 203 248
Line -1 false 205 249 218 235
Line -1 false 218 235 200 144

bird1
false
0
Polygon -7500403 true true 2 6 2 39 270 298 297 298 299 271 187 160 279 75 276 22 100 67 31 0

bird2
false
0
Polygon -7500403 true true 2 4 33 4 298 270 298 298 272 298 155 184 117 289 61 295 61 105 0 43

boat1
false
0
Polygon -1 true false 63 162 90 207 223 207 290 162
Rectangle -6459832 true false 150 32 157 162
Polygon -13345367 true false 150 34 131 49 145 47 147 48 149 49
Polygon -7500403 true true 158 33 230 157 182 150 169 151 157 156
Polygon -7500403 true true 149 55 88 143 103 139 111 136 117 139 126 145 130 147 139 147 146 146 149 55

boat2
false
0
Polygon -1 true false 63 162 90 207 223 207 290 162
Rectangle -6459832 true false 150 32 157 162
Polygon -13345367 true false 150 34 131 49 145 47 147 48 149 49
Polygon -7500403 true true 157 54 175 79 174 96 185 102 178 112 194 124 196 131 190 139 192 146 211 151 216 154 157 154
Polygon -7500403 true true 150 74 146 91 139 99 143 114 141 123 137 126 131 129 132 139 142 136 126 142 119 147 148 147

boat3
false
0
Polygon -1 true false 63 162 90 207 223 207 290 162
Rectangle -6459832 true false 150 32 157 162
Polygon -13345367 true false 150 34 131 49 145 47 147 48 149 49
Polygon -7500403 true true 158 37 172 45 188 59 202 79 217 109 220 130 218 147 204 156 158 156 161 142 170 123 170 102 169 88 165 62
Polygon -7500403 true true 149 66 142 78 139 96 141 111 146 139 148 147 110 147 113 131 118 106 126 71

box
true
0
Polygon -7500403 true true 45 255 255 255 255 45 45 45

butterfly1
true
0
Polygon -16777216 true false 151 76 138 91 138 284 150 296 162 286 162 91
Polygon -7500403 true true 164 106 184 79 205 61 236 48 259 53 279 86 287 119 289 158 278 177 256 182 164 181
Polygon -7500403 true true 136 110 119 82 110 71 85 61 59 48 36 56 17 88 6 115 2 147 15 178 134 178
Polygon -7500403 true true 46 181 28 227 50 255 77 273 112 283 135 274 135 180
Polygon -7500403 true true 165 185 254 184 272 224 255 251 236 267 191 283 164 276
Line -7500403 true 167 47 159 82
Line -7500403 true 136 47 145 81
Circle -7500403 true true 165 45 8
Circle -7500403 true true 134 45 6
Circle -7500403 true true 133 44 7
Circle -7500403 true true 133 43 8

circle
false
0
Circle -7500403 true true 35 35 230

person
false
0
Circle -7500403 true true 155 20 63
Rectangle -7500403 true true 158 79 217 164
Polygon -7500403 true true 158 81 110 129 131 143 158 109 165 110
Polygon -7500403 true true 216 83 267 123 248 143 215 107
Polygon -7500403 true true 167 163 145 234 183 234 183 163
Polygon -7500403 true true 195 163 195 233 227 233 206 159

sheep
false
15
Rectangle -1 true true 90 75 270 225
Circle -1 true true 15 75 150
Rectangle -16777216 true false 81 225 134 286
Rectangle -16777216 true false 180 225 238 285
Circle -16777216 true false 1 88 92

spacecraft
true
0
Polygon -7500403 true true 150 0 180 135 255 255 225 240 150 180 75 240 45 255 120 135

thin-arrow
true
0
Polygon -7500403 true true 150 0 0 150 120 150 120 293 180 293 180 150 300 150

truck-down
false
0
Polygon -7500403 true true 225 30 225 270 120 270 105 210 60 180 45 30 105 60 105 30
Polygon -8630108 true false 195 75 195 120 240 120 240 75
Polygon -8630108 true false 195 225 195 180 240 180 240 225

truck-left
false
0
Polygon -7500403 true true 120 135 225 135 225 210 75 210 75 165 105 165
Polygon -8630108 true false 90 210 105 225 120 210
Polygon -8630108 true false 180 210 195 225 210 210

truck-right
false
0
Polygon -7500403 true true 180 135 75 135 75 210 225 210 225 165 195 165
Polygon -8630108 true false 210 210 195 225 180 210
Polygon -8630108 true false 120 210 105 225 90 210

turtle
true
0
Polygon -7500403 true true 138 75 162 75 165 105 225 105 225 142 195 135 195 187 225 195 225 225 195 217 195 202 105 202 105 217 75 225 75 195 105 187 105 135 75 142 75 105 135 105

wolf
false
0
Rectangle -7500403 true true 15 105 105 165
Rectangle -7500403 true true 45 90 105 105
Polygon -7500403 true true 60 90 83 44 104 90
Polygon -16777216 true false 67 90 82 59 97 89
Rectangle -1 true false 48 93 59 105
Rectangle -16777216 true false 51 96 55 101
Rectangle -16777216 true false 0 121 15 135
Rectangle -16777216 true false 15 136 60 151
Polygon -1 true false 15 136 23 149 31 136
Polygon -1 true false 30 151 37 136 43 151
Rectangle -7500403 true true 105 120 263 195
Rectangle -7500403 true true 108 195 259 201
Rectangle -7500403 true true 114 201 252 210
Rectangle -7500403 true true 120 210 243 214
Rectangle -7500403 true true 115 114 255 120
Rectangle -7500403 true true 128 108 248 114
Rectangle -7500403 true true 150 105 225 108
Rectangle -7500403 true true 132 214 155 270
Rectangle -7500403 true true 110 260 132 270
Rectangle -7500403 true true 210 214 232 270
Rectangle -7500403 true true 189 260 210 270
Line -7500403 true 263 127 281 155
Line -7500403 true 281 155 281 192

wolf-left
false
3
Polygon -6459832 true true 117 97 91 74 66 74 60 85 36 85 38 92 44 97 62 97 81 117 84 134 92 147 109 152 136 144 174 144 174 103 143 103 134 97
Polygon -6459832 true true 87 80 79 55 76 79
Polygon -6459832 true true 81 75 70 58 73 82
Polygon -6459832 true true 99 131 76 152 76 163 96 182 104 182 109 173 102 167 99 173 87 159 104 140
Polygon -6459832 true true 107 138 107 186 98 190 99 196 112 196 115 190
Polygon -6459832 true true 116 140 114 189 105 137
Rectangle -6459832 true true 109 150 114 192
Rectangle -6459832 true true 111 143 116 191
Polygon -6459832 true true 168 106 184 98 205 98 218 115 218 137 186 164 196 176 195 194 178 195 178 183 188 183 169 164 173 144
Polygon -6459832 true true 207 140 200 163 206 175 207 192 193 189 192 177 198 176 185 150
Polygon -6459832 true true 214 134 203 168 192 148
Polygon -6459832 true true 204 151 203 176 193 148
Polygon -6459832 true true 207 103 221 98 236 101 243 115 243 128 256 142 239 143 233 133 225 115 214 114

wolf-right
false
3
Polygon -6459832 true true 170 127 200 93 231 93 237 103 262 103 261 113 253 119 231 119 215 143 213 160 208 173 189 187 169 190 154 190 126 180 106 171 72 171 73 126 122 126 144 123 159 123
Polygon -6459832 true true 201 99 214 69 215 99
Polygon -6459832 true true 207 98 223 71 220 101
Polygon -6459832 true true 184 172 189 234 203 238 203 246 187 247 180 239 171 180
Polygon -6459832 true true 197 174 204 220 218 224 219 234 201 232 195 225 179 179
Polygon -6459832 true true 78 167 95 187 95 208 79 220 92 234 98 235 100 249 81 246 76 241 61 212 65 195 52 170 45 150 44 128 55 121 69 121 81 135
Polygon -6459832 true true 48 143 58 141
Polygon -6459832 true true 46 136 68 137
Polygon -6459832 true true 45 129 35 142 37 159 53 192 47 210 62 238 80 237
Line -16777216 false 74 237 59 213
Line -16777216 false 59 213 59 212
Line -16777216 false 58 211 67 192
Polygon -6459832 true true 38 138 66 149
Polygon -6459832 true true 46 128 33 120 21 118 11 123 3 138 5 160 13 178 9 192 0 199 20 196 25 179 24 161 25 148 45 140
Polygon -6459832 true true 67 122 96 126 63 144

@#$#@#$#@
NetLogo 3.0
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