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Real people aren’t identical - let’s give our turtles individual differences.

Giving Turtles Different Properties

Random assignment:

create-turtles 100 [
  set age 18 + random 62        ; Age between 18-79
  set wealth random 10000       ; Wealth between $0-$9,999
  set social-activity random 11 ; Social activity 0-10
]

Systematic assignment:

create-turtles 100 [
  set age 20 + who / 2          ; Age increases with ID
  if who < 50 [ set color red ] ; First 50 are red
  if who >= 50 [ set color blue ] ; Last 50 are blue
]

Using probability distributions:

create-turtles 100 [
  ; Most people are middle-aged, few are very young or old
  set age 20 + random-normal 25 10
  
  ; 70% are cooperative, 30% are competitive  
  if random 100 < 70 [ set strategy "cooperative" ]
  if random 100 >= 70 [ set strategy "competitive" ]
]

Random vs. Systematic Assignment

Random assignment creates natural variation:

Systematic assignment creates patterns:

Using who Numbers to Identify Specific Turtles

Every turtle has a unique who number (0, 1, 2, 3, ...):

ask turtle 0 [ set color red ]        ; Color turtle #0 red
ask turtle 5 [ forward 10 ]           ; Move turtle #5 forward
ask turtles with [who < 10] [ ... ]   ; First 10 turtles
ask turtles with [who mod 2 = 0] [ ... ] ; Even-numbered turtles

Activity 2: Random Walk

Goal: Make turtles explore randomly

to setup
  clear-all
  create-turtles 20 [
    setxy random-xcor random-ycor
    set color one-of [red green blue yellow orange]
    set size 1 + random 2  ; Size between 1-3
  ]
end

to go
  ask turtles [
    right random 360       ; Turn random direction
    forward 1              ; Move forward
    if xcor > max-pxcor or xcor < min-pxcor [ 
      set xcor random-xcor ; Wrap around edges
    ]
    if ycor > max-pycor or ycor < min-pycor [
      set ycor random-ycor ; Wrap around edges  
    ]
  ]
end

Run this: Click “setup” once, then click “go” repeatedly to watch random exploration.

Course Modules
Creating and Controlling Turtles (20 min)
Course Modules
Turtle Interactions (15 min)