ModelId:

animal1

SimileVersion:

5.9

This models the dynamics of a population of animals, represented as a set of individuals that come into existence, live for a while, then die. When the animals are alive, they move around according to a simple random walk.

Equations:

**Equations in Desktop**

N = sum({one})

**Equations in ANIMAL**

X: initial value = rand(30,70)

Y: initial value = rand(30,70)

Dir: initial value = rand(0,6.28)

create = 100

r = rand(0,2*0.7)

m = 0.6

xchange = (if outside == 1 then speed*cos(dir+3.14) else speed*cos(dir))

dirchange = (if outside == 1 then 3.14/dt(1) else rand(-0.4,0.4)/dt(1))

ychange = (if outside == 1 then speed*sin(dir+3.14) else speed*sin(dir))

speed = 5

size = 3

outside = (if (x<0;x>100;y<0;y>100)then 1 else 0)

one = 1

Results:

Attachment | Size |
---|---|

animal1.sml | 95.71 KB |

animal1.shf | 2.1 KB |

Model tags: