Learning Goals

  1. Familiarity with three types of models
    1. Sorting/Tipping
    2. Peer Effects
    3. Cellular Automata
  2. Introduction to coding

1 Dimensional Cellular Automata

Download and play with CA-1Dsimulator.xlsx

Game of Life

Life is played on a grid of square cells—like a chess board but extending infinitely in every direction. A cell can be live or dead. A live cell is shown by putting a marker on its square. A dead cell is shown by leaving the square empty. Each cell in the grid has a neighborhood consisting of the eight cells in every direction including diagonals.

To apply one step of the rules, we count the number of live neighbors for each cell. What happens next depends on this number.

A dead cell with exactly three live neighbors becomes a live cell (birth).
birth0.gif birth1.gif
A live cell with two or three live neighbors stays alive (survival).
surv0.gif surv1.gif surv2.gif
In all other cases, a cell dies or remains dead (overcrowding or loneliness).
death0.gif death1.gif death2.gif death3.gif

Note: The number of live neighbors is always based on the cells before the rule was applied. In other words, we must first find all of the cells that change before changing any of them. Sounds like a job for a computer!

Try out some of the patterns on Paul Callahan's What is the game of life? page.

Try out the game of life on Netlogo (either online in browser or in local Netlogo in the models library]

Granovetter Models

Download and play with problems-0172-0175.xlsx

Standing Ovations

Excel Model

File nameFile typeSize
birth0.gifGIF image data211 BytesInfo
birth1.gifGIF image data203 BytesInfo
CA-1Dsimulator.xlsxNo description324.86 kBInfo
death0.gifGIF image data182 BytesInfo
death1.gifGIF image data245 BytesInfo
death2.gifGIF image data141 BytesInfo
death3.gifGIF image data181 BytesInfo
problems-0172-0175.xlsxNo description60.84 kBInfo
surv0.gifGIF image data163 BytesInfo
surv1.gifGIF image data177 BytesInfo
surv2.gifGIF image data179 BytesInfo