;; declarations globals [ ;; max-creature-speed ;; max speed of a creature ;; alga-initial-mass ;; initial mass of an alga ;; herbivore-initial-mass ;; initial mass of a herbivore ;; carnivore-initial-mass ;; initial mass of a carnivore ;; probability-direction-change ;; probability that creature changes direction while moving ;; weight-consumption-min ;; minimal (absolute) weight consumption ;; weight-consupmtion-pct-herbivore ;; percentual weight consumption of herbivores ;; weight-consupmtion-pct-carnivore ;; percentual weight consumption of herbivores ;; algae-sprout-ticks ;; number of ticks, after which new algae grow ;; algae-sprout-amount ;; number of individual alga in one grow ;; splitting-threshold-1 ;; creatures split when big enough, this is first threshold (multiple of mass) ;; splitting-probability-1 ;; probability creature will split itself when bigger than threshold ;; splitting-threshold-2 ;; analogous to those above ;; splitting-probability-2 ;; algae-setup-count ;; initial count of alga ;; herbivores-setup-count ;; initial count of herbivores ;; carnivores-setup-count ;; initial count of carnivores last-algae-sprouting ;; global counter how many go loops passed since last algae regrowth ] ;; all creatures - algae and protozoa. ;; basically a name placeholder for turtles breed [creatures creature] creatures-own [ creature-type ;; alga / herbivore / carnivore mass ;; mass. also used as a radius of circular body speed ;; a speed of a creature already-existing ;; if it does exist or not (useful when creating new creatures) weight-consumption-pct ;; on every turn, creature consumes energy contained in its own weight initial-mass ;; initial (default) mass, 1 for AL, 3 for HP, 5 for CP ] ;; load predefined models to load-most-stable-ecosystem reset-all-settings set algae-setup-count 468 set herbivores-setup-count 74 set carnivores-setup-count 16 set algae-sprout-ticks 18 set algae-sprout-amount 24 setup end to load-minimal-stable-ecosystem reset-all-settings set algae-setup-count 200 set herbivores-setup-count 50 set carnivores-setup-count 50 set algae-sprout-ticks 6 set algae-sprout-amount 11 setup end ;; fuzzing methods to hot-fuzz file-open "C:\\skola\\vse\\simsys\\out\\out.csv" file-print "algae-setup-count,herbivores-setup-count,carnivores-setup-count,algae-sprout-ticks,algae-sprout-amount,ecosystem-stability-rate" file-flush let fuzz-num 0 while [fuzz-num < 10] [ fuzz set fuzz-num (fuzz-num + 1) ] file-close-all end to fuzz reset-all-settings set algae-setup-count (random 500 + 1) set herbivores-setup-count (random 100 + 1) set carnivores-setup-count (random 100 + 1) set algae-sprout-ticks (random 30 + 1) set algae-sprout-amount (random 50 + 1) ;; number of tests model has to pass let i 0 let j 0 let stable-counter 0 while [i < 100] [ show (word "running model: " i) setup let early-break false set j 0 while [(not early-break) and j < 10000] [ go set j (j + 1) ;;for better performance if ((count creatures with [creature-type = "carnivore"] <= 0) or (count creatures with [creature-type = "herbivore"] <= 0)) [ show "early break" set early-break true ] ] if ((count creatures with [creature-type = "carnivore"] > 0) and (count creatures with [creature-type = "herbivore"] > 0) and (count creatures with [creature-type = "alga"] > 0)) [ set stable-counter (stable-counter + 1) ] set i (i + 1) ] file-print (word algae-setup-count "," herbivores-setup-count "," carnivores-setup-count "," algae-sprout-ticks "," algae-sprout-amount "," (stable-counter / 100)) file-flush end ;; setup and go methods to reset-all-settings set algae-setup-count 10 set herbivores-setup-count 10 set carnivores-setup-count 10 set algae-sprout-ticks 10 set algae-sprout-amount 2 reset-model-internal-settings end to reset-model-internal-settings set max-creature-speed 1 set alga-initial-mass 1 set herbivore-initial-mass 3 set carnivore-initial-mass 5 set probability-direction-change 0.05 set weight-consumption-min 0.001 set weight-consupmtion-pct-herbivore 0.0025 set weight-consupmtion-pct-carnivore 0.005 set splitting-threshold-1 2 set splitting-probability-1 0.25 set splitting-threshold-2 3 set splitting-probability-2 0.5 end to setup clear-all ;; setup environment set-default-shape creatures "circle" ask patches [ set pcolor sky - 2 ] ;; init counters set last-algae-sprouting 0 ;; create creatures breed-algae algae-setup-count breed-herbivores herbivores-setup-count breed-carnivores carnivores-setup-count reset-ticks end to go ;; try to sprout algae ;; cannot be done by "every" construct because that would ;; screw up simulation when not using normal speed sprout-algae ;; everybody move! ask creatures [ forward speed ] ;; collision evaluation, breeding, etc. goes here check-collisions ;; commence intercourse! each with oneself... cell-split ;; creatures consume energy (their own weight) ;; those with 0 weight die consume-weight ;; change direction ask creatures [ set heading (new-direction heading) ] tick end ;; other methods ;; This method checks for collisions between creatures. It is based on ;; comparing distance of their centers (sum of radii) and sum of masses. ;; Because mass = radius and (icon) size = diameter. to check-collisions ask creatures [ let my-x xcor let my-y ycor let my-id who let my-mass mass ask other creatures [ if ((distancexy my-x my-y) < (my-mass + mass)) [ process-collision my-id who ((distancexy my-x my-y) - (my-mass + mass)) ] ] ] end ;; If collission is detected, this method is called. Takes ids of creatures and ;; longest distance they are overlapping themselves. This distance is then used if ;; one of creatures has to "back off". to process-collision [creature1-id creature2-id distance-delta] ;; some creatures from the list already died, do not process if ((creature creature1-id) = nobody or (creature creature2-id) = nobody) [ stop ] let creature1-mass [mass] of creature creature1-id let creature1-type [creature-type] of creature creature1-id let creature2-mass [mass] of creature creature2-id let creature2-type [creature-type] of creature creature2-id ;; if (creature1-type = "alga" and creature2-type = "alga") [ ;; show "alga collides alga. should not happen" ;; ] if (creature1-type = "alga" and creature2-type = "herbivore") [ ifelse (creature1-mass >= creature2-mass) [ ;; alga is bigger, herbivore backs off resolve-back-off creature2-id creature1-id distance-delta ] [ ;; alga is smaller, herbivore eats it process-eating creature2-id creature1-id ] ] if (creature1-type = "alga" and creature2-type = "carnivore") [ ifelse (creature1-mass >= creature2-mass) [ ;; alga is bigger, carnivore backs off resolve-back-off creature2-id creature1-id distance-delta ] [ ;; alga is smaller, carnivore destroys it process-nonweight-eating creature2-id creature1-id ] ] if (creature1-type = "herbivore" and creature2-type = "herbivore") [ ifelse (creature1-mass >= creature2-mass) [ ;; herbivore1 is bigger, herbivore2 backs off resolve-back-off creature2-id creature1-id distance-delta ] [ ;; herbivore2 is bigger, herbivore1 backs off resolve-back-off creature1-id creature2-id distance-delta ] ] if (creature1-type = "herbivore" and creature2-type = "carnivore") [ ifelse (creature1-mass >= creature2-mass) [ ;; herbivore is bigger, carnivore backs off resolve-back-off creature2-id creature1-id distance-delta ] [ ;; herbivore is smaller, carnivore eats it process-eating creature2-id creature1-id ] ] if (creature1-type = "carnivore" and creature2-type = "carnivore") [ ifelse (creature1-mass = creature2-mass) [ ;; both carnivores are of equal size, one of them backs off resolve-back-off creature2-id creature1-id distance-delta ] [ if (creature1-mass < creature2-mass) [ ;; carnivore1 is bigger, eats carnivore2 process-eating creature2-id creature1-id ] ] ] end ;; Whe two creatures meet and one cannot eat the other, the smaller must back off. ;; This method takes the situation when they are overlapping and sets things right ;; by changing heading of creature the other way and movind it by abs(distance-delta). to resolve-back-off [creature-who creature-who-away-from distance-delta] ask creature creature-who [ face (turtle creature-who-away-from) set heading (heading + 180) forward (abs distance-delta) ] end ;; When two creatures meet and one can eat other and gain mass from it, this method is called. ;; It adds mass to the eater creature and dies food creature. to process-eating [eater-id food-id] let gain-mass 0 ask creature food-id [ set gain-mass mass die ] ask creature eater-id [ set mass (mass + gain-mass) set size (2 * mass) ] end ;; When carnivore meets alga, it destroys it and does not gain mass in the process. ;; This method is called - it simply die the alga creature. to process-nonweight-eating [eater-id food-id] ask creature food-id [ die ] end ;; This method ensures random placement of creatures in such a way they do not overlap. ;; Takes care about new creatures only. ;; ;; *** IMPORTANT *** ;; This methos is called from breed-* and not from breed-creatures because ;; breed-creatures does not know about mass. to place-nonconflicting [creature-id] let is-colliding true let max-placement-retries 500 ask creature creature-id [ setxy random-xcor random-ycor ] while [is-colliding and max-placement-retries > 0] [ let my-x [xcor] of creature creature-id let my-y [ycor] of creature creature-id let my-mass [mass] of creature creature-id ;; This line HAS TO be here. If it is in "ask other" block, ;; we end up in infinite loop when breeding one creature when ;; calling "breed-* 1" as first breed call during setup. set max-placement-retries (max-placement-retries - 1) ask other creatures [ ifelse ((distancexy my-x my-y) < (my-mass + mass)) [ ask creature creature-id [ setxy random-xcor random-ycor ] set max-placement-retries (max-placement-retries - 1) ] [ set is-colliding false ] ] ] end ;; This method asks all creatures to split themselves. Splitting probability is given by two thresholds. ;; By default, creature with 2*mass has 25% chance of splitting, creature with over 3*mass has 50% probability ;; of splitting. Filters out algae. to cell-split ask creatures [ if (creature-type != "alga") [ ;;mass over 2*initial-mass if (((mass >= (splitting-threshold-1 * initial-mass)) and ;;but below 3*initial-mass (mass < (splitting-threshold-2 * initial-mass)) and ;;generate random [0;1) and when lower than 0.25 ((random-float 1) <= splitting-probability-1)) or ;;mass over 3*initial-mass ((mass >= (splitting-threshold-2 * initial-mass)) and ;;generate random [0;1) and when lower than 0.5 ((random-float 1) <= splitting-probability-2))) [ set size mass ;;make original creature half the size and move it forward (mass / 2) set mass (mass / 2) hatch 1 [ ;;hatch a clone and move it in opposite direction set heading (heading + 180) forward (mass * 2) ] ] ] ] end ;; This method implements weight decrease of creatures based on their type. to consume-weight ask creatures [ if (creature-type = "herbivore") [ do-weight-decrease weight-consupmtion-pct-herbivore ] if (creature-type = "carnivore") [ do-weight-decrease weight-consupmtion-pct-carnivore ] ] end ;; This method realizes actual mass decrease. Also adjusts size of creature sprite ;; and dies-off all creatures with mass 0 or lower. to do-weight-decrease [decrease-pct] let mass-decrease (mass * decrease-pct) if (mass-decrease < weight-consumption-min) [ set mass-decrease weight-consumption-min ] let new-mass (mass - mass-decrease) ifelse (new-mass > 0) [ set mass new-mass set size (2 * mass) ] [ die ] end ;; This method tries to create new algae every few ticks. ;; Amount and frequency are global variables. to sprout-algae ifelse (last-algae-sprouting > algae-sprout-ticks) [ breed-algae algae-sprout-amount set last-algae-sprouting 0 ] [ set last-algae-sprouting (last-algae-sprouting + 1) ] end ;; This method sets up many general creatures. It is not called directly ;; but only from breed-algae, breed-herbivores and breed-carnivores which complete ;; the creatures setup. to breed-creatures [amount] create-creatures amount ask creatures [ if (already-existing != true) [ ;; setting speed for new creature => random speed ;; the 0.000000000001 is here as simplest-possible fix to non-moving creatures ;; generally there is no better way to do it if we want speed from (0;max] set speed (random-float max-creature-speed) + 0.000000000001 ] ] end ;; This method sets up new algae. ;; Contrary to herbivore/carnivore variants, breed-algae is also called within ;; go loop, simulating algae regrowth. to breed-algae [amount] breed-creatures amount ask creatures [ if (already-existing != true) [ ;; setting up our new algae set creature-type "alga" set mass alga-initial-mass set speed 0 set color green set size (2 * mass) place-nonconflicting who set already-existing true ] ] end ;; This method sets up new herbivores. to breed-herbivores [amount] breed-creatures amount ask creatures [ if (already-existing != true) [ ;; setting up our new herbivores set creature-type "herbivore" set mass herbivore-initial-mass set color yellow set size (2 * mass) place-nonconflicting who set already-existing true set weight-consumption-pct weight-consupmtion-pct-herbivore set initial-mass mass ] ] end ;; This method sets up new carnivores. to breed-carnivores [amount] breed-creatures amount ask creatures [ if (already-existing != true) [ ;; setting up our new carnivores set creature-type "carnivore" set mass carnivore-initial-mass set color red set size (2 * mass) place-nonconflicting who set already-existing true set weight-consumption-pct weight-consupmtion-pct-carnivore set initial-mass mass ] ] end ;; There is a 5% probability that a creature changes its direction. ;; Method generates a random number x from [0;1) and if x <= 0.05, new direction ;; is generated and returned. ;; If x > 0.05, old direction is returned. to-report new-direction [previous-direction] let direction previous-direction if (random-float 1 <= probability-direction-change) [ set direction (random-float 360) ] report direction end @#$#@#$#@ GRAPHICS-WINDOW 426 10 1078 683 -1 -1 2.0 1 10 1 1 1 0 1 1 1 0 320 0 320 0 0 1 ticks 30.0 BUTTON 16 247 399 280 NIL setup NIL 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 18 317 400 350 NIL go T 1 T OBSERVER NIL NIL NIL NIL 1 SLIDER 9 496 203 529 max-creature-speed max-creature-speed 0 3 1 0.01 1 NIL HORIZONTAL SLIDER 9 535 203 568 probability-direction-change probability-direction-change 0 1 0.05 0.01 1 NIL HORIZONTAL SLIDER 230 457 402 490 alga-initial-mass alga-initial-mass 1 25 1 1 1 NIL HORIZONTAL SLIDER 230 496 402 529 herbivore-initial-mass herbivore-initial-mass 1 25 3 1 1 NIL HORIZONTAL SLIDER 230 535 402 568 carnivore-initial-mass carnivore-initial-mass 1 25 5 1 1 NIL HORIZONTAL BUTTON 429 848 686 881 NIL reset-all-settings NIL 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 428 744 687 777 NIL reset-model-internal-settings NIL 1 T OBSERVER NIL NIL NIL NIL 1 SLIDER 11 640 399 673 weight-consumption-min weight-consumption-min 0 2 0.001 0.001 1 NIL HORIZONTAL SLIDER 11 676 399 709 weight-consupmtion-pct-herbivore weight-consupmtion-pct-herbivore 0 1 0.0025 0.0005 1 NIL HORIZONTAL SLIDER 12 712 400 745 weight-consupmtion-pct-carnivore weight-consupmtion-pct-carnivore 0 1 0.005 0.0005 1 NIL HORIZONTAL SLIDER 16 167 400 200 algae-sprout-ticks algae-sprout-ticks 0 100 10 1 1 NIL HORIZONTAL SLIDER 16 207 399 240 algae-sprout-amount algae-sprout-amount 0 100 2 1 1 NIL HORIZONTAL SLIDER 14 899 186 932 splitting-threshold-1 splitting-threshold-1 1 10 2 1 1 NIL HORIZONTAL SLIDER 14 937 186 970 splitting-probability-1 splitting-probability-1 0 1 0.25 0.01 1 NIL HORIZONTAL SLIDER 226 899 398 932 splitting-threshold-2 splitting-threshold-2 1 10 3 1 1 NIL HORIZONTAL SLIDER 226 939 398 972 splitting-probability-2 splitting-probability-2 0 1 0.5 0.01 1 NIL HORIZONTAL INPUTBOX 16 102 143 162 algae-setup-count 10 1 0 Number INPUTBOX 145 102 271 162 herbivores-setup-count 10 1 0 Number INPUTBOX 274 102 400 162 carnivores-setup-count 10 1 0 Number TEXTBOX 19 23 399 93 Insert startup counts of algae, herbivores and carnivores. Sliders adjust algae regrowth rate in terms of frequency - each algae-sprout-ticks alga regrows. Count of new alga is set by algae-sprout-amount.\n\nAdjust as necessary and hit \"setup\". 11 0.0 1 TEXTBOX 94 294 355 312 Hit \"go\" to run the model. Hit it again to pause it. 11 0.0 1 TEXTBOX 50 379 379 412 Those are model internal variables. You can adjust them as needed. If you screw up, use buttons at the bottom to reset to deafults. 11 0.0 1 TEXTBOX 10 421 207 491 Each creature has randomly generated speed from the interval 0.0000001 (this is hardwired) to max-creature-speed.\nThere is probability-direction-change, that creature changes its moving direction. 11 0.0 1 TEXTBOX 243 424 409 454 Each type of creature has initial mass (mass given upon creation). 11 0.0 1 TEXTBOX 12 581 402 638 Herbivores and carnivores need energy to live. This energy is measured as a reduction of mass of a creature (its radius). It applies over time. It is measured in percents and can be different for different types of cretures. But it is at least weight-consumption-min (absolute value) to ensure death of feeble ones. 11 0.0 1 TEXTBOX 14 756 409 896 Each creature (except alga) can hatch new ones. Because we are simulating cells, they simply split in two, halving the mass.\nThere are two thresholds on multiples of initial size. When mass is over (splitting-threshold-1 * initial-mass) but below (splitting-threshold-2 * initial-mass), it happens with splitting-probability-1. When mass of a creature is over (splitting-threshold-2 * initial-mass), it happens with splitting-probability-2.\n\nIf you set splitting-threshold-1 over splitting-threshold-2, only splitting-threshold-2 will take effect. THIS IS BAD SETTING! Just use splitting-probability-X = 0 when you want to use just one threshold. 11 0.0 1 TEXTBOX 428 698 693 752 This button will reset only internal settings of a model. Setup counts and algae regrowth settings will remain untouched. 11 0.0 1 TEXTBOX 429 787 699 844 This button resets all settings to defaults. Does not destroy the model. If you want to return to default model after fiddling with sliders, use reset-all-settings and then just hit \"setup\". 11 0.0 1 PLOT 1084 10 1486 285 Cretures count Time Creatures 0.0 10.0 0.0 10.0 true true "" "" PENS "algae" 1.0 0 -10899396 true "" "plot count creatures with [creature-type = \"alga\"]" "herbivores" 1.0 0 -1184463 true "" "plot count creatures with [creature-type = \"herbivore\"]" "carnivores" 1.0 0 -2674135 true "" "plot count creatures with [creature-type = \"carnivore\"]" MONITOR 1085 289 1208 334 Algae count count creatures with [creature-type = \"alga\"] 17 1 11 MONITOR 1212 289 1344 334 Herbivores count count creatures with [creature-type = \"herbivore\"] 17 1 11 MONITOR 1348 289 1487 334 Carnivores count count creatures with [creature-type = \"carnivore\"] 17 1 11 PLOT 1085 336 1487 533 Creatures overall mass Time Sum(mass) 0.0 10.0 0.0 10.0 true false "" "" PENS "algae" 1.0 0 -10899396 true "" "plot sum [mass] of creatures with [creature-type = \"alga\"]" "herbivores" 1.0 0 -1184463 true "" "plot sum [mass] of creatures with [creature-type = \"herbivore\"]" "carnivore" 1.0 0 -2674135 true "" "plot sum [mass] of creatures with [creature-type = \"carnivore\"]" MONITOR 1086 539 1277 584 Biggest creature mass (without algae) max [mass] of creatures with [creature-type != \"alga\"] 10 1 11 MONITOR 1086 588 1279 633 Smallest creature mass (without algae) min [mass] of creatures with [creature-type != \"alga\"] 10 1 11 MONITOR 1087 637 1283 682 Average creature mass (without algae) mean [mass] of creatures with [creature-type != \"alga\"] 10 1 11 MONITOR 1293 539 1487 584 Fastest creature speed (without algae) max [speed] of creatures 10 1 11 MONITOR 1293 588 1488 633 Slowest creature speed (without algae) min [speed] of creatures with [creature-type != \"alga\"] 10 1 11 MONITOR 1289 636 1489 681 Average creature speed (without algae) mean [speed] of creatures with [creature-type != \"alga\"] 10 1 11 BUTTON 735 743 990 776 NIL load-most-stable-ecosystem NIL 1 T OBSERVER NIL NIL NIL NIL 1 BUTTON 736 847 994 880 NIL load-minimal-stable-ecosystem NIL 1 T OBSERVER NIL NIL NIL NIL 1 TEXTBOX 736 698 990 729 Load parameters for most stable model we managed to find. About 14% chance of becoming stable. 11 0.0 1 TEXTBOX 738 797 1008 828 Load parameters for minimal stable ecosystem we managed to find. About 1% chance of becoming stable. 11 0.0 1 @#$#@#$#@ ## WHAT IS IT? (a general understanding of what the model is trying to show or explain) ## HOW IT WORKS (what rules the agents use to create the overall behavior of the model) ## HOW TO USE IT (how to use the model, including a description of each of the items in the Interface tab) ## THINGS TO NOTICE (suggested things for the user to notice while running the model) ## THINGS TO TRY (suggested things for the user to try to do (move sliders, switches, etc.) with the model) ## EXTENDING THE MODEL (suggested things to add or change in the Code tab to make the model more complicated, detailed, accurate, etc.) ## NETLOGO FEATURES (interesting or unusual features of NetLogo that the model uses, particularly in the Code tab; or where workarounds were needed for missing features) ## RELATED MODELS (models in the NetLogo Models Library and elsewhere which are of related interest) ## CREDITS AND REFERENCES (a reference to the model's URL on the web if it has one, as well as any other necessary credits, citations, and links) @#$#@#$#@ default true 0 Polygon -7500403 true true 150 5 40 250 150 205 260 250 airplane true 0 Polygon -7500403 true true 150 0 135 15 120 60 120 105 15 165 15 195 120 180 135 240 105 270 120 285 150 270 180 285 210 270 165 240 180 180 285 195 285 165 180 105 180 60 165 15 arrow true 0 Polygon -7500403 true true 150 0 0 150 105 150 105 293 195 293 195 150 300 150 box false 0 Polygon -7500403 true true 150 285 285 225 285 75 150 135 Polygon -7500403 true true 150 135 15 75 150 15 285 75 Polygon -7500403 true true 15 75 15 225 150 285 150 135 Line -16777216 false 150 285 150 135 Line -16777216 false 150 135 15 75 Line -16777216 false 150 135 285 75 bug true 0 Circle -7500403 true true 96 182 108 Circle -7500403 true true 110 127 80 Circle -7500403 true true 110 75 80 Line -7500403 true 150 100 80 30 Line -7500403 true 150 100 220 30 butterfly true 0 Polygon -7500403 true true 150 165 209 199 225 225 225 255 195 270 165 255 150 240 Polygon -7500403 true true 150 165 89 198 75 225 75 255 105 270 135 255 150 240 Polygon -7500403 true true 139 148 100 105 55 90 25 90 10 105 10 135 25 180 40 195 85 194 139 163 Polygon -7500403 true true 162 150 200 105 245 90 275 90 290 105 290 135 275 180 260 195 215 195 162 165 Polygon -16777216 true false 150 255 135 225 120 150 135 120 150 105 165 120 180 150 165 225 Circle -16777216 true false 135 90 30 Line -16777216 false 150 105 195 60 Line -16777216 false 150 105 105 60 car false 0 Polygon -7500403 true true 300 180 279 164 261 144 240 135 226 132 213 106 203 84 185 63 159 50 135 50 75 60 0 150 0 165 0 225 300 225 300 180 Circle -16777216 true false 180 180 90 Circle -16777216 true false 30 180 90 Polygon -16777216 true false 162 80 132 78 134 135 209 135 194 105 189 96 180 89 Circle -7500403 true true 47 195 58 Circle -7500403 true true 195 195 58 circle false 0 Circle -7500403 true true 0 0 300 circle 2 false 0 Circle -7500403 true true 0 0 300 Circle -16777216 true false 30 30 240 cow false 0 Polygon -7500403 true true 200 193 197 249 179 249 177 196 166 187 140 189 93 191 78 179 72 211 49 209 48 181 37 149 25 120 25 89 45 72 103 84 179 75 198 76 252 64 272 81 293 103 285 121 255 121 242 118 224 167 Polygon -7500403 true true 73 210 86 251 62 249 48 208 Polygon -7500403 true true 25 114 16 195 9 204 23 213 25 200 39 123 cylinder false 0 Circle -7500403 true true 0 0 300 dot false 0 Circle -7500403 true true 90 90 120 face happy false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Polygon -16777216 true false 150 255 90 239 62 213 47 191 67 179 90 203 109 218 150 225 192 218 210 203 227 181 251 194 236 217 212 240 face neutral false 0 Circle -7500403 true true 8 7 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Rectangle -16777216 true false 60 195 240 225 face sad false 0 Circle -7500403 true true 8 8 285 Circle -16777216 true false 60 75 60 Circle -16777216 true false 180 75 60 Polygon -16777216 true false 150 168 90 184 62 210 47 232 67 244 90 220 109 205 150 198 192 205 210 220 227 242 251 229 236 206 212 183 fish false 0 Polygon -1 true false 44 131 21 87 15 86 0 120 15 150 0 180 13 214 20 212 45 166 Polygon -1 true false 135 195 119 235 95 218 76 210 46 204 60 165 Polygon -1 true false 75 45 83 77 71 103 86 114 166 78 135 60 Polygon -7500403 true true 30 136 151 77 226 81 280 119 292 146 292 160 287 170 270 195 195 210 151 212 30 166 Circle -16777216 true false 215 106 30 flag false 0 Rectangle -7500403 true true 60 15 75 300 Polygon -7500403 true true 90 150 270 90 90 30 Line -7500403 true 75 135 90 135 Line -7500403 true 75 45 90 45 flower false 0 Polygon -10899396 true false 135 120 165 165 180 210 180 240 150 300 165 300 195 240 195 195 165 135 Circle -7500403 true true 85 132 38 Circle -7500403 true true 130 147 38 Circle -7500403 true true 192 85 38 Circle -7500403 true true 85 40 38 Circle -7500403 true true 177 40 38 Circle -7500403 true true 177 132 38 Circle -7500403 true true 70 85 38 Circle -7500403 true true 130 25 38 Circle -7500403 true true 96 51 108 Circle -16777216 true false 113 68 74 Polygon -10899396 true false 189 233 219 188 249 173 279 188 234 218 Polygon -10899396 true false 180 255 150 210 105 210 75 240 135 240 house false 0 Rectangle -7500403 true true 45 120 255 285 Rectangle -16777216 true false 120 210 180 285 Polygon -7500403 true true 15 120 150 15 285 120 Line -16777216 false 30 120 270 120 leaf false 0 Polygon -7500403 true true 150 210 135 195 120 210 60 210 30 195 60 180 60 165 15 135 30 120 15 105 40 104 45 90 60 90 90 105 105 120 120 120 105 60 120 60 135 30 150 15 165 30 180 60 195 60 180 120 195 120 210 105 240 90 255 90 263 104 285 105 270 120 285 135 240 165 240 180 270 195 240 210 180 210 165 195 Polygon -7500403 true true 135 195 135 240 120 255 105 255 105 285 135 285 165 240 165 195 line true 0 Line -7500403 true 150 0 150 300 line half true 0 Line -7500403 true 150 0 150 150 pentagon false 0 Polygon -7500403 true true 150 15 15 120 60 285 240 285 285 120 person false 0 Circle -7500403 true true 110 5 80 Polygon -7500403 true true 105 90 120 195 90 285 105 300 135 300 150 225 165 300 195 300 210 285 180 195 195 90 Rectangle -7500403 true true 127 79 172 94 Polygon -7500403 true true 195 90 240 150 225 180 165 105 Polygon -7500403 true true 105 90 60 150 75 180 135 105 plant false 0 Rectangle -7500403 true true 135 90 165 300 Polygon -7500403 true true 135 255 90 210 45 195 75 255 135 285 Polygon -7500403 true true 165 255 210 210 255 195 225 255 165 285 Polygon -7500403 true true 135 180 90 135 45 120 75 180 135 210 Polygon -7500403 true true 165 180 165 210 225 180 255 120 210 135 Polygon -7500403 true true 135 105 90 60 45 45 75 105 135 135 Polygon -7500403 true true 165 105 165 135 225 105 255 45 210 60 Polygon -7500403 true true 135 90 120 45 150 15 180 45 165 90 sheep false 15 Circle -1 true true 203 65 88 Circle -1 true true 70 65 162 Circle -1 true true 150 105 120 Polygon -7500403 true false 218 120 240 165 255 165 278 120 Circle -7500403 true false 214 72 67 Rectangle -1 true true 164 223 179 298 Polygon -1 true true 45 285 30 285 30 240 15 195 45 210 Circle -1 true true 3 83 150 Rectangle -1 true true 65 221 80 296 Polygon -1 true true 195 285 210 285 210 240 240 210 195 210 Polygon -7500403 true false 276 85 285 105 302 99 294 83 Polygon -7500403 true false 219 85 210 105 193 99 201 83 square false 0 Rectangle -7500403 true true 30 30 270 270 square 2 false 0 Rectangle -7500403 true true 30 30 270 270 Rectangle -16777216 true false 60 60 240 240 star false 0 Polygon -7500403 true true 151 1 185 108 298 108 207 175 242 282 151 216 59 282 94 175 3 108 116 108 target false 0 Circle -7500403 true true 0 0 300 Circle -16777216 true false 30 30 240 Circle -7500403 true true 60 60 180 Circle -16777216 true false 90 90 120 Circle -7500403 true true 120 120 60 tree false 0 Circle -7500403 true true 118 3 94 Rectangle -6459832 true false 120 195 180 300 Circle -7500403 true true 65 21 108 Circle -7500403 true true 116 41 127 Circle -7500403 true true 45 90 120 Circle -7500403 true true 104 74 152 triangle false 0 Polygon -7500403 true true 150 30 15 255 285 255 triangle 2 false 0 Polygon -7500403 true true 150 30 15 255 285 255 Polygon -16777216 true false 151 99 225 223 75 224 truck false 0 Rectangle -7500403 true true 4 45 195 187 Polygon -7500403 true true 296 193 296 150 259 134 244 104 208 104 207 194 Rectangle -1 true false 195 60 195 105 Polygon -16777216 true false 238 112 252 141 219 141 218 112 Circle -16777216 true false 234 174 42 Rectangle -7500403 true true 181 185 214 194 Circle -16777216 true false 144 174 42 Circle -16777216 true false 24 174 42 Circle -7500403 false true 24 174 42 Circle -7500403 false true 144 174 42 Circle -7500403 false true 234 174 42 turtle true 0 Polygon -10899396 true false 215 204 240 233 246 254 228 266 215 252 193 210 Polygon -10899396 true false 195 90 225 75 245 75 260 89 269 108 261 124 240 105 225 105 210 105 Polygon -10899396 true false 105 90 75 75 55 75 40 89 31 108 39 124 60 105 75 105 90 105 Polygon -10899396 true false 132 85 134 64 107 51 108 17 150 2 192 18 192 52 169 65 172 87 Polygon -10899396 true false 85 204 60 233 54 254 72 266 85 252 107 210 Polygon -7500403 true true 119 75 179 75 209 101 224 135 220 225 175 261 128 261 81 224 74 135 88 99 wheel false 0 Circle -7500403 true true 3 3 294 Circle -16777216 true false 30 30 240 Line -7500403 true 150 285 150 15 Line -7500403 true 15 150 285 150 Circle -7500403 true true 120 120 60 Line -7500403 true 216 40 79 269 Line -7500403 true 40 84 269 221 Line -7500403 true 40 216 269 79 Line -7500403 true 84 40 221 269 wolf false 0 Polygon -16777216 true false 253 133 245 131 245 133 Polygon -7500403 true true 2 194 13 197 30 191 38 193 38 205 20 226 20 257 27 265 38 266 40 260 31 253 31 230 60 206 68 198 75 209 66 228 65 243 82 261 84 268 100 267 103 261 77 239 79 231 100 207 98 196 119 201 143 202 160 195 166 210 172 213 173 238 167 251 160 248 154 265 169 264 178 247 186 240 198 260 200 271 217 271 219 262 207 258 195 230 192 198 210 184 227 164 242 144 259 145 284 151 277 141 293 140 299 134 297 127 273 119 270 105 Polygon -7500403 true true -1 195 14 180 36 166 40 153 53 140 82 131 134 133 159 126 188 115 227 108 236 102 238 98 268 86 269 92 281 87 269 103 269 113 x false 0 Polygon -7500403 true true 270 75 225 30 30 225 75 270 Polygon -7500403 true true 30 75 75 30 270 225 225 270 @#$#@#$#@ NetLogo 5.3.1 @#$#@#$#@ @#$#@#$#@ @#$#@#$#@ @#$#@#$#@ @#$#@#$#@ default 0.0 -0.2 0 0.0 1.0 0.0 1 1.0 0.0 0.2 0 0.0 1.0 link direction true 0 Line -7500403 true 150 150 90 180 Line -7500403 true 150 150 210 180 @#$#@#$#@ 0 @#$#@#$#@