Adam Campbell's Website
Totalistic cellular automata

  • A 1D cellular automata consists of a row of "cells" and a replacement rule. Each cell can be in one of three states: {0, 1, 2}, or more appropriately {white, red, cyan}. Initially every cell is in state 0 (white), except the middle cell which starts in state 1 (red). To get the new value of a cell, its value is averaged with its left and right neighbors from the current time step. After the average is computed, it is used as an index into the lookup table. This table is shown in the applet as 7 larger rectangles and and arrow pointing to 7 squares.
  • As you can see, the rows of cells expand infinitely, but because a computer does not have infinite memory, the row length must be finite. The row size is 50,000 cells, and the row is actually circular (cell 1 is a neighbor of cell 50,000.)
  • The rule numbers correspond to those on page 60 of Stephen Wolfram's book "A New Kind of Science".
  • Click the box next to Restart to start running the CA from the initial black cell.
  • Pause simply pauses the applet.
  • Init. random will randomly seed the initial configuration of the cells when the Restart box is pressed.
  • The seven columns of colors will allow you to change the three colors used in the cellular automata. Click a box in the first column to change the first color, etc.
  • Click inside the seven boxes on the right of the arrows to change the replacement rule. Notice how is cycles through the three colors.
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