# Four-Color Outer Median Cellular Automata on the Grid

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Outer median cellular automata (CA) are a functional form of the CellularAutomaton function in *Mathematica*. The color of the active cell on the next step is determined by first taking the median of the neighbors of the active cell up to a certain radius and then taking the floor of the median. In two dimensions, radius 1 means the eight neighbors around the central active cell, and radius 2 means out to the sixteen neighbors around the eight neighbors around the central active cell. The pairs {active cell color, floor of median of neighbors} are then mapped to rules in color spaces as usual. Here there are four colors.

Contributed by: Abigail Nussey (March 2011)

Open content licensed under CC BY-NC-SA

## Snapshots

## Details

Developed as part of a project for the 2008 NKS Summer School (*NKS|Online*).

## Permanent Citation

"Four-Color Outer Median Cellular Automata on the Grid"

http://demonstrations.wolfram.com/FourColorOuterMedianCellularAutomataOnTheGrid/

Wolfram Demonstrations Project

Published: March 7 2011