Simple Walk NetLogo Model

Produced for the book series "Exercises for Artificial Intelligence";

Author: W. J. Teahan; Publisher: Ventus Publishing Aps, Denmark.

view/download model file: Simple-Walk.nlogo

WHAT IS IT?

This model illustrates solutions to Exercises 4.2.1 and 4.2.2 for the book "Exercises for Artificial Intelligence - Agents and Environments".

HOW TO USE IT

Press the setup-maze button first, then press the setup-turtle button. The walk button will execute the solution for Exercise 4.2.1. The shortest-walk-1, shortest-walk-2 and shortest-walk-3 buttons will execute solutions for Exercise 4.2.2.

CREDITS AND REFERENCES

To refer to this model in publications, please use:

Teahan, W. J. (2010). Simple-Walk NetLogo model.
Exercisaes for Artificial Intelligence. Ventus Publishing Aps.

PROCEDURES

; Simple Walk model.
; .
;
; Copyright 2010 William John Teahan. All Rights Reserved.
;

to setup-maze
  ca ;; clear everything
  
  ask patches
  [ set pcolor white ] ;; make background full of white patches
 
  ask patches
  [
    if (pxcor = 30) and (pycor >= -30) and (pycor <= 30)
      [ set pcolor black ]
    if (pxcor = -30) and (pycor >= -30) and (pycor <= 30)
      [ set pcolor black ]

    if (pycor = 30) and (pxcor >= -30) and (pxcor <= 30)
      [ set pcolor black ]
    if (pycor = -30) and (pxcor >= -30) and (pxcor <= 30)
      [ set pcolor black ]
  ]

end

to setup-turtle
  create-turtles 1
  [ set color red
    set size 5
    setxy 0 -28
    set heading 0
    pen-down
    set pen-size 2
  ]
end

to walk
  ask turtles
  [
    left 90
    forward 28
    right 90
    forward 56
    right 90
    forward 56
    right 90  
  ]
end

to shortest-walk-1
; A solution if only right-angled turns are allowed.
  ask turtles
  [
    forward 56
    right 90
    forward 28
    right 90
  ]
end

to shortest-walk-2
; A solution with the shortest number of steps?

  ask turtles
  [
    setxy 30 30
    ; right some-angle
    ; (work out the value of Òsome-angleÓ for yourself)
  ]
end

to shortest-walk-3
; Another solution, slightly more steps.

  ask turtles
  [
    facexy 30 30
    forward sqrt (56 * 56 + 28 * 28)
    ; (using square of the hypotenuse)
    right (180 - 26.6)
    ; (using angle calculation for a right angle triangle)

  ]
end
;
; Copyright 2010 by William John Teahan.  All rights reserved.
;
; Permission to use, modify or redistribute this model is hereby granted,
; provided that both of the following requirements are followed:
; a) this copyright notice is included.
; b) this model will not be redistributed for profit without permission
;    from William John Teahan.
; Contact William John Teahan for appropriate licenses for redistribution for
; profit.
;
; To refer to this model in publications, please use:
;
; Teahan, W. J. (2010).  Simple Walk NetLogo model.
;   Artificial Intelligence. Ventus Publishing Aps
;