NetLogo User Community Models
by Carlos Pedro Gonçalves (Submitted: 06/26/2003)
WHAT IS IT?
This is a simulation of a model inspired in Per Bak's pile of sand
HOW IT WORKS
Each site in a plane world has a certain height (which was set to have a minimum of 0 and a maximum of 4).
THINGS TO NOTICE
Notice how the system advances towards criticality, and how, after it attains criticality the mean height is approximately constant.
THINGS TO TRY
It would be interesting to try and change the world's shape, this changes the borders of the world, and changing the rules in accordance.
EXTENDING THE MODEL
The code is divided into three sections, in each of these sections there are changes that can be made. Here are some suggestions of extensions for each section:
Section 1 - The World:
Instead of a random initial configuration of heights it might be interesting to add the feature of allowing the user to personalize the landscape or to choose between random and different non-random initial configurations.
Section 2 - Main Procedure for the Pile of Sand
Possible extensions could be different rules.
Section 3 - Statistical Analysis
Try adding new statistical quantities.
CREDITS AND REFERENCES
The main reference for this model was Per Bak's book:
Quand la Nature S'Organise, Translated by Marcel Filoche, Flammarion, Paris, 1999.
(back to the NetLogo User Community Models)