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Basic animal/particle movement model - Model catalogue -

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Basic animal/particle movement model

Model : move1
Simile version : 3.1+
Date added : 2003-06-25
Keywords : Movement ; Individual-based ; Particles ;


This is a basic random-walk model for a set of individuals in 2D space. The individuals could represent animals wandering around on a plane surface.

An individual has a tendency to keep on moving in the same direction, but in any one time step can deviate to left or right. The deviation is determined randomly, by selecting a value from a random distribution with a mean of 0 (degrees). If the spread of this distribution is large (say, from -50 degrees to +50 degrees), the animal will have a very windy path. If the spread is small (say, -2 degrees to +2 degrees), the animal’s path will be pretty straight.

When the animal reaches the edge of the area (100x100 units), it reverses direction.

Because the movement model is inside a multiple-instance submodel, we are modelling the movement of a collection of individuals. Note that, in this model, there is no interaction between these individuals: they all move independently of each other. To add interaction between individuals into this model, we would need to add an association submodel, with a condition that makes an association between two individuals when they are within a certain distnace of each other.


Model file

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The following image (animated when viewed in a web browser) shows the position of the individuals at the start of the simulation, and at intervals thereafter.