MIHS-17 Michael M, Nicole H
Model was written in NetLogo 6.0.2
•
Viewed 94 times
•
Downloaded 15 times
•
Run 0 times
Do you have questions or comments about this model? Ask them here! (You'll first need to log in.)
Info tab cannot be displayed because of an encoding error
Comments and Questions
Please start the discussion about this model!
(You'll first need to log in.)
Click to Run Model
globals [ max-cows ] ; don't let cows population grow too large ; cows and wolves are both breeds of turtle. breed [ cows cow ] ; cows is its own plural, so we use "a-cows" as the singular. breed [ wolves wolf ] breed [ humans human ] turtles-own [ energy ] ; both wolves and cows have energy patches-own [ countdown ] to setup clear-all ifelse netlogo-web? [set max-cows 10000] [set max-cows 30000] ; Check model-version switch ; if we're not modeling grass, then the cows don't need to eat to survive ; otherwise the grass's state of growth and growing logic need to be set up ifelse model-version = "cows-wolves-grass" [ ask patches [ set pcolor one-of [ green brown ] ifelse pcolor = green [ set countdown grass-regrowth-time ] [ set countdown random grass-regrowth-time ] ; initialize grass regrowth clocks randomly for brown patches ] ] [ ask patches [ set pcolor green ] ] create-cows initial-number-cows ; create the cows, then initialize their variables [ set shape "cow" set color white set size 3 ; easier to see set label-color blue - 2 set energy random (2 * cows-gain-from-food) setxy random-xcor random-ycor ] create-wolves initial-number-wolves ; create the wolves, then initialize their variables [ set shape "wolf" set color black set size 2 ; easier to see set energy random (2 * wolf-gain-from-food) setxy random-xcor random-ycor ] create-humans initial-number-humans ; create the cows, then initialize their variables [ set shape "person" set color turquoise set size 2 ; easier to see set label-color blue - 2 set energy random (2 * cows-gain-from-food) setxy random-xcor random-ycor ] display-labels reset-ticks end to go ; stop the simulation of no wolves or cows if not any? turtles [ stop ] ; stop the model if there are no wolves and the number of cows gets very large if not any? wolves and count cows > max-cows [ user-message "Humans have killed every living organism on the planet" stop ] ask cows [ move if model-version = "cows-wolves-grass" [ ; in this version, cows eat grass, grass grows and it costs cows energy to move set energy energy - 1 ; deduct energy for cows only if running cows-wolf-grass model version eat-grass ; cows eat grass only if running cows-wolf-grass model version death ; cows die from starvation only if running cows-wolf-grass model version ] reproduce-cows ; cows reproduce at random rate governed by slider ] ask wolves [ move set energy energy - 1 ; wolves lose energy as they move eat-cows ; wolves eat a cows on their patch death ; wolves die if our of energy reproduce-wolves ; wolves reproduce at random rate governed by slider ] if model-version = "cows-wolves-grass" [ ask patches [ grow-grass ] ] ; set grass count patches with [pcolor = green] tick display-labels ask humans [ move set energy energy ; eat-wolves ; death ; reproduce-humans ; ] end to move ; turtle procedure rt random 50 lt random 50 fd 1 end to eat-grass ; cows procedure ; cows eat grass, turn the patch brown if pcolor = green [ set pcolor brown set energy energy + cows-gain-from-food ; cows gain energy by eating ] end to reproduce-cows ; cows procedure if random-float 100 < cows-reproduce [ ; throw "dice" to see if you will reproduce set energy (energy / 2) ; divide energy between parent and offspring hatch 1 [ rt random-float 360 fd 1 ] ; hatch an offspring and move it forward 1 step ] end to reproduce-wolves ; wolf procedure if random-float 100 < wolf-reproduce [ ; throw "dice" to see if you will reproduce set energy (energy / 2) ; divide energy between parent and offspring hatch 1 [ rt random-float 360 fd 1 ] ; hatch an offspring and move it forward 1 step ] end to reproduce-humans ; wolf procedure if random-float 100 < human-reproduce [ ; throw "dice" to see if you will reproduce set energy (energy / 2) ; divide energy between parent and offspring hatch 1 [ rt random-float 360 fd 1 ] ; hatch an offspring and move it forward 1 step ] end to eat-cows ; wolf procedure let prey one-of cows-here ; grab a random cows if prey != nobody [ ; did we get one? if so, ask prey [ die ] ; kill it, and... set energy energy + wolf-gain-from-food + human-gain-from-food ; get energy from eating ] end to eat-humans ; wolf procedure let prey one-of humans-here ; grab a random cows if prey != nobody [ ; did we get one? if so, ask prey [ die ] ; kill it, and... set energy energy + wolf-gain-from-food ; get energy from eating ] end to eat-wolves ; human procedure let prey one-of wolves-here ; grab a random cows if prey != nobody [ ; did we get one? if so, ask prey [ die ] ; kill it, and... set energy energy + human-gain-from-food ; get energy from eating ] end to death ; turtle procedure (i.e. both wolf nd cows procedure) ; when energy dips below zero, die if energy < 0 [ die ] end to grow-grass ; patch procedure ; countdown on brown patches: if reach 0, grow some grass if pcolor = brown [ ifelse countdown <= 0 [ set pcolor green set countdown grass-regrowth-time ] [ set countdown countdown - 1 ] ] end to-report grass ifelse model-version = "cows-wolves-grass" [ report patches with [pcolor = green] ] [ report 0 ] end to display-labels ask turtles [ set label "" ] if show-energy? [ ask wolves [ set label round energy ] if model-version = "cows-wolves-grass" [ ask cows [ set label round energy ] ] ] end ; Copyright 1997 Uri Wilensky. ; See Info tab for full copyright and license.
There is only one version of this model, created over 6 years ago by Nicole H.
This model does not have any ancestors.
This model does not have any descendants.