forked from Estavaringo/virus-propagation
-
Notifications
You must be signed in to change notification settings - Fork 0
/
ep_complexos.nlogo
1004 lines (857 loc) · 29 KB
/
ep_complexos.nlogo
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
globals
[
nb-infected-previous ;; Number of infected people at the previous tick
city ;; The patches representing the grey city
forest ;; The patches representing the grey city
angle ;; Heading for individuals
beta-n ;; The average number of new secondary infections per infected this tick
gamma ;; The average number of new recoveries per infected this tick
r0 ;; The number of secondary infections that arise due to a single infective introduced in a wholly susceptible population
max-infection-length
immunity-length
]
turtles-own
[
infected? ;; If true, the person is infected.
infected-forever?
immunity?
immunity-remaining
turtle-type ;; Which type a turtle is, people or animal.
human-infect-probability
animal-infect-probability
infection-length
]
;;TO-DO - CITY EXPANDING
patches-own
[
resistence
]
;;;
;;; SETUP PROCEDURES
;;;
to setup
clear-all
setup-globals
setup-people
reset-ticks
end
to setup-globals
;;;set max-infection-length 24 * 7
set max-infection-length 24 * max-infection-length-days
;;;set immunity-length 24 * 14
set immunity-length 24 * immunity-length-days
set city patches with [member? patch pxcor pycor get-initial-city initial-city-radius]
ask city [ set pcolor gray ]
set forest patches with [not member? patch pxcor pycor get-initial-city initial-city-radius]
ask forest [ set pcolor green ]
end
to-report get-initial-city [radius]
let patchesList []
ask patch max-pxcor max-pycor
[
ask patches in-radius radius
[
set patchesList lput patch pxcor pycor patchesList
]
]
report patchesList
end
;; TODO fazer a movimentação
;; Create initial-people number of people.
;; Those that live on the left are squares; those on the right, circles.
to setup-people
create-turtles initial-people
[ let random-patch one-of city
setxy [pxcor] of random-patch [pycor] of random-patch
set turtle-type "person"
set infected? false
set infected-forever? false
set immunity? false
set shape "person"
set human-infect-probability human-probability-to-infect-human
set animal-infect-probability human-probability-to-infect-animal
set infection-length 0
assign-color
]
create-turtles initial-animals
[ let random-patch one-of forest
setxy [pxcor] of random-patch [pycor] of random-patch
set turtle-type "animal"
set infected? false
set infected-forever? false
set immunity? false
set shape "cow"
set human-infect-probability animal-probability-to-infect-human
set animal-infect-probability animal-probability-to-infect-animal
set infection-length 0
if (random-float 1 < initial-animals-infected)
[
set infected? true
set infected-forever? true
]
assign-color
]
end
;; red is an infected person
;; white is not infected
to assign-color ;; turtle procedure
ifelse turtle-type = "person"
[set color white]
[set color black]
if infected?
[set color red]
end
;;;
;;; GO PROCEDURES
;;;
to go
;;if all? turtles [ not infected? ]
;;[ stop ]
ask turtles [ move ]
ask turtles [
ifelse immunity-remaining > 0
[set immunity-remaining (immunity-remaining - 1)]
[set immunity? false]
]
ask turtles [ if infected? [ recover ]]
ask turtles [if infected? [ set infection-length (infection-length + 1) ]]
ask turtles [ if infected? [ infect ] ]
ask turtles[ assign-color]
if mouse-down? [
ask patch (round mouse-xcor) (round mouse-ycor) [
if member? self city [set pcolor green]
if member? self forest [set pcolor gray]
set city patches with[pcolor = gray]
set forest patches with[pcolor = green]
]
]
tick
end
to move ;; turtle procedure
if turtle-type = "person"
[
if member? patch-here city ;; and on city patch
[
set angle random-float 360
let new-patch patch-at-heading-and-distance angle 1
if new-patch != nobody and member? new-patch city
[
move-to new-patch
]
]
if member? patch-here forest ;; and on city patch
[
set angle random-float 360
let new-patch patch-at-heading-and-distance angle 1
if new-patch != nobody and member? new-patch city
[
move-to new-patch
]
]
]
if turtle-type = "animal"
[ ;; in forest
ifelse member? patch-here city ;; and on city patch
[
set angle random-float 360
let new-patch patch-at-heading-and-distance angle 1
if new-patch != nobody and not member? new-patch city
[
move-to new-patch
]
]
[
set angle random-float 360
let new-patch patch-at-heading-and-distance angle 1
if new-patch != nobody and not member? new-patch city
[
move-to new-patch
]
]
]
end
;; Infected individuals who are not isolated or hospitalized have a chance of transmitting their disease to their susceptible neighbors.
;; If the neighbor is linked, then the chance of disease transmission doubles.
to infect ;; turtle procedure
let caller self
let nearby-uninfected (turtles-on neighbors)
with [ not infected? ]
if nearby-uninfected != nobody
[
ask nearby-uninfected
[
if not immunity?
[
ifelse turtle-type = "person"
[
if (random-float 1 < [human-infect-probability] of caller) ;; twice as likely to infect a linked person
[
set infected? true
set infection-length 0
]
]
[
if (random-float 1 < [animal-infect-probability] of caller)
[
set infected? true
set infection-length 0
]
]
]
]
]
end
to recover
if infection-length = max-infection-length and not infected-forever?
[
set infected? false
set immunity? true
set immunity-remaining immunity-length
]
end
; Copyright 2011 Uri Wilensky.
; See Info tab for full copyright and license.
@#$#@#$#@
GRAPHICS-WINDOW
646
27
1129
511
-1
-1
19.0
1
10
1
1
1
0
0
0
1
-12
12
-12
12
0
0
1
hours
30.0
BUTTON
410
375
493
408
setup
setup
NIL
1
T
OBSERVER
NIL
NIL
NIL
NIL
1
BUTTON
505
375
588
408
go
go
T
1
T
OBSERVER
NIL
NIL
NIL
NIL
0
SLIDER
15
65
290
98
initial-people
initial-people
10
100
40.0
5
1
NIL
HORIZONTAL
PLOT
15
420
405
563
Populations
hours
# people
0.0
10.0
0.0
100.0
true
true
"" ""
PENS
"Infected" 1.0 0 -2674135 true "" "plot count turtles with [ (infected? and turtle-type = \"person\")]"
"Not Infected" 1.0 0 -10899396 true "" "plot count turtles with [ not infected? and turtle-type = \"person\"]"
SLIDER
310
65
585
98
initial-animals
initial-animals
10
100
20.0
5
1
NIL
HORIZONTAL
SLIDER
15
310
290
343
initial-city-radius
initial-city-radius
0
30
26.0
0.5
1
NIL
HORIZONTAL
SLIDER
15
100
290
133
human-probability-to-infect-human
human-probability-to-infect-human
0
1
0.04
0.01
1
NIL
HORIZONTAL
SLIDER
310
100
585
133
animal-probability-to-infect-human
animal-probability-to-infect-human
0
1
0.09
0.01
1
NIL
HORIZONTAL
SLIDER
310
135
585
168
animal-probability-to-infect-animal
animal-probability-to-infect-animal
0
1
0.05
0.01
1
NIL
HORIZONTAL
SLIDER
15
135
290
168
human-probability-to-infect-animal
human-probability-to-infect-animal
0
1
0.03
0.01
1
NIL
HORIZONTAL
SLIDER
310
310
585
343
urban-growth-rate
urban-growth-rate
0
1
0.0
0.01
1
NIL
HORIZONTAL
SLIDER
15
220
290
253
max-infection-length-days
max-infection-length-days
1
120
7.0
1
1
NIL
HORIZONTAL
SLIDER
310
220
585
253
immunity-length-days
immunity-length-days
1
120
14.0
1
1
NIL
HORIZONTAL
TEXTBOX
20
25
170
51
Human
24
0.0
1
TEXTBOX
315
30
465
56
Animal
24
0.0
1
TEXTBOX
20
185
170
211
Infection
24
0.0
1
TEXTBOX
15
275
165
301
City
24
0.0
1
TEXTBOX
15
385
165
411
Graphs
24
0.0
1
PLOT
15
580
405
730
Animals
hours
animals
0.0
364.0
0.0
100.0
true
false
"" ""
PENS
"Infected" 1.0 0 -8053223 true "" "plot count turtles with [ (infected? and turtle-type = \"animal\")]"
"Not Infected" 1.0 0 -15040220 true "" "plot count turtles with [ (not infected? and turtle-type = \"animal\")]"
SLIDER
310
175
585
208
initial-animals-infected
initial-animals-infected
0
1
0.1
0.01
1
NIL
HORIZONTAL
@#$#@#$#@
## WHAT IS IT?
This model is an extension of the basic model of epiDEM (a curricular unit which stands for Epidemiology: Understanding Disease Dynamics and Emergence through Modeling). It simulates the spread of an infectious disease in a semi-closed population, but with additional features such as travel, isolation, quarantine, inoculation, and links between individuals. However, we still assume that the virus does not mutate, and that upon recovery, an individual will have perfect immunity.
Overall, this model helps users:
1) understand the emergent disease spread dynamics in relation to the changes in control measures, travel, and mobility
2) understand how the reproduction number, R_0, represents the threshold for an epidemic
3) understand the relationship between derivatives and integrals, represented simply as rates and cumulative number of cases, and
4) provide opportunities to extend or change the model to include some properties of a disease that interest users the most.
## HOW IT WORKS
Individuals wander around the world in random motion. There are two groups of individuals, represented as either squares or circles, and are geographically divided by the yellow border. Upon coming into contact with an infected person, he or she has a chance of contracting the illness. Depending on their tendencies, which are set by the user, sick individuals will either isolate themselves at "home," go to a hospital, be force-quarantined into a hospital by health officials, or just move about. An infected individual has a chance of recovery after the given recovery time has elapsed.
The presence of the virus in the population is represented by the colors of individuals. Four colors are used: white individuals are uninfected, red individuals are infected, green individuals are recovered, and blue individuals are inoculated. Once recovered, the individual is permanently immune to the virus. The yellow person symbolizes the health official or ambulance, who patrols the world in search of ill people. Once coming in contact with an infected individual, the ambulance immediately delivers the infected to the hospital within the region of residence.
The graph INFECTION AND RECOVERY RATES shows the rate of change of the cumulative infected and recovered in the population. It tracks the average number of secondary infections and recoveries per tick. The reproduction number is calculated under different assumptions than those of the KM model, as we allow for more than one infected individual in the population, and introduce aforementioned variables.
At the end of the simulation, the R_0 reflects the estimate of the reproduction number, the final size relation that indicates whether there will be (or there was, in the model sense) an epidemic. This again closely follows the mathematical derivation that R_0 = beta*S(0)/ gamma = N*ln(S(0) / S(t)) / (N - S(t)), where N is the total population, S(0) is the initial number of susceptibles, and S(t) is the total number of susceptibles at time t. In this model, the R_0 estimate is the number of secondary infections that arise for an average infected individual over the course of the person's infected period.
## HOW TO USE IT
The SETUP button creates individuals according to the parameter values chosen by the user. Each individual has a 5% chance of being initialized as infected. Once the simulation has been setup, push the GO button to run the model. GO starts the simulation and runs it continuously until GO is pushed again.
Each time-step can be considered to be in hours, although any suitable time unit will do.
What follows is a summary of the sliders in the model.
INITIAL-PEOPLE (initialized to vary between 50 - 400): The total number of individuals the simulation begins with.
INFECTION-CHANCE (10 - 50): Probability of disease transmission from one individual to another.
RECOVERY-CHANCE (10 - 100): Probability of an individual's recovery once the infection has lasted longer than the person's recovery time.
AVERAGE-RECOVERY-TIME (50 - 300): Time it takes for an individual to recover, on average. The actual individual's recovery time is pulled from a normal distribution centered around the AVERAGE-RECOVERY-TIME at its mean, with a standard deviation of a quarter of the AVERAGE-RECOVERY-TIME. Each time-step can be considered to be in hours, although any suitable time unit will do.
AVERAGE-ISOLATION-TENDENCY (0 - 50): Average tendency of individuals to isolate themselves and will not spread the disease. Once an infected person is identified as an "isolator," the individual will isolate himself in the current location (as indicated by the grey patch) and will stay there until full recovery.
AVERAGE-HOSPITAL-GOING-TENDENCY (0 - 50): Average tendency of individuals to go to a hospital when sick. If an infected person is identified as a "hospital goer," then he or she will go to the hospital, and will recover in half the time of an average recovery period, due to better medication and rest.
INITIAL-AMBULANCE (0 - 4): Number of health officials or ambulances that move about at random, and force-quarantine sick individuals upon contact. The health officials are immune to the disease, and they themselves do not physically accompany the patient to the hospital. They move at a speed 5 times as fast as other individuals in the world and are not bounded by geographic region.
INOCULATION-CHANCE (0 - 50): Probability of an individual getting vaccinated, and hence immune from the virus.
INTRA-MOBILITY (0 - 1): This indicates how "mobile" an individual is. Usually, an individual at each time step moves by a distance 1. In this model, the person will move at a distance indicated by the INTRA-MOBILITY at each time-step. Thus, the lower the intra-mobility level, the less the movement in the individuals. Individuals move randomly by this assigned value; ambulances always move 5 times faster than this assigned value.
In addition, there are two switches, and a related slider:
LINKS? : When ON, there will be links randomly assigned between people, and the disease will spread twice as fast to those that the infected person is linked with as to the others. When OFF, the disease spreads with an equal chance to those around the infected person.
TRAVEL? : When ON, people from the two regions (separated by the yellow border in the middle) are allowed to migrate and mix. When OFF, the people stay in the region in which they live.
TRAVEL-TENDENCY (0 - 1): When TRAVEL? is ON, this slider indicates the probability of an individual to be traveling at each tick. The 1 indicates a 1 percent chance of travel per tick.
A number of graphs are also plotted in this model.
CUMULATIVE INFECTED AND RECOVERED: This plots the total percentage of individuals who have ever been infected or recovered.
POPULATIONS: This plots the number of people with or without the disease.
INFECTION AND RECOVERY RATES: This plots the estimated rates at which the disease is spreading. BetaN is the rate at which the cumulative infected changes, and Gamma rate at which the cumulative recovered changes.
R_0: This is an estimate of the reproduction number.
## THINGS TO NOTICE
As with many epidemiological models, the number of people becoming infected over time, in the event of an epidemic, traces out an "S-curve." It is called an S-curve because it is shaped like a sideways S. By changing the values of the parameters using the slider, try to see what kinds of changes make the S curve stretch or shrink.
Whenever there's a spread of the disease that reaches most of the population, we say that there was an epidemic. The reproduction number serves as an indicator for the likeliness of an epidemic to occur, if it is greater than 1. If it is smaller than 1, then it is likely that the disease spread will stop short, and we call this an endemic.
Notice how the introduction of various human behaviors, such as travel, inoculation, isolation and quarantine, help constrain the spread of the disease, and what changes that brings to the population level in terms of rate and time taken of disease spread, as well as the population affected.
## THINGS TO TRY
Compare this model with the epiDEM basic model. Do the added complexities significantly change the disease spread? What kinds of changes bring about interesting outcomes?
Notice the difference in dynamics when the travel chooser is on versus off. What happens to the population and the disease spread in both cases?
Does the disease spread change when the link chooser is on? What about when you increase the number of ambulances? What happens to the number of people infected?
Based on this model, what are some strategies or preventive measures that you think are important to undertake on the onset of a disease outbreak? Are there some that are more effective than others? Why might that be? What combinations work well? Are there some measures that seem redundant?
## EXTENDING THE MODEL
Are there other ways to change the behavior of the people once they are infected? Try to think about how you would introduce such a variable.
In this model, we introduce an option for travel, so that there is mixing between two otherwise closed populations. What happens when you introduce births and deaths to each region or just one?
What would happen when the virus mutates? How will that change the population dynamic and disease spread?
What would happen if the population had a mix of healthy and less healthy people, so as to have differing levels of susceptibility?
## NETLOGO FEATURES
Notice that each agent pulls from a truncated normal distribution, centered around the AVERAGE-RECOVERY-TIME set by the user, to determine its recovery-time. This is to account for the variation in genetic differences and the immune system functions of individuals. Similarly, an individual's isolation-tendency and hospital-going-tendency are pulled from truncated normal distributions centered around AVERAGE-ISOLATION-TENDENCY and AVERAGE-HOSPITAL-GOING-TENDENCY respectively.
Notice that R_0 calculated in this model is a numerical estimate to the analytic R_0. In the special case of one infective introduced to a wholly susceptible population (i.e., the Kermack-McKendrick assumptions), the numerical estimations of R_0 are very close to the analytic values. With added complexity in the models, such as the introduction of travel and control measures, the analytic R_0 becomes harder to derive. The numerical estimation is therefore a crude measure of what the actual R_0 might be.
In addition to travel and control measures, notice that this model introduces links amongst individuals and the individual's mobility, which also affect the dynamics of the disease transmission.
## RELATED MODELS
epiDEM basic, HIV, Virus and Virus on a Network are related models.
## HOW TO CITE
If you mention this model or the NetLogo software in a publication, we ask that you include the citations below.
For the model itself:
* Yang, C. and Wilensky, U. (2011). NetLogo epiDEM Travel and Control model. http://ccl.northwestern.edu/netlogo/models/epiDEMTravelandControl. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.
Please cite the NetLogo software as:
* Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.
## COPYRIGHT AND LICENSE
Copyright 2011 Uri Wilensky.
![CC BY-NC-SA 3.0](http://ccl.northwestern.edu/images/creativecommons/byncsa.png)
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License. To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-sa/3.0/ or send a letter to Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
Commercial licenses are also available. To inquire about commercial licenses, please contact Uri Wilensky at uri@northwestern.edu.
<!-- 2011 Cite: Yang, C. -->
@#$#@#$#@
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
person lefty
false
0
Circle -7500403 true true 170 5 80
Polygon -7500403 true true 165 90 180 195 150 285 165 300 195 300 210 225 225 300 255 300 270 285 240 195 255 90
Rectangle -7500403 true true 187 79 232 94
Polygon -7500403 true true 255 90 300 150 285 180 225 105
Polygon -7500403 true true 165 90 120 150 135 180 195 105
person righty
false
0
Circle -7500403 true true 50 5 80
Polygon -7500403 true true 45 90 60 195 30 285 45 300 75 300 90 225 105 300 135 300 150 285 120 195 135 90
Rectangle -7500403 true true 67 79 112 94
Polygon -7500403 true true 135 90 180 150 165 180 105 105
Polygon -7500403 true true 45 90 0 150 15 180 75 105
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
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
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 6.1.1
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
@#$#@#$#@
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