Challenge 9

How to Track a Turtle

Challenge

Do you feel as if you have been wandering around aimlessly?  Have you been traveling across patches with no particular destination?  Do you wish that you could gain some direction?  Well look no further!  You can get the direction you desire from a command that lets you head towards any other turtle, as long as you know its who number.  That versatile command is:

seth towards xcor-of whonumber ycor-of whonumber

This command sets the heading of the turtles in the direction of the turtle whonumber.

Now that you know the secret to finding some direction, build a project in which turtles head towards a moving target (another turtle).  You might want to build this behavior into one of your previous projects or try starting with one of these ideas:

·        Build a game of tag in which the “it” chooses and seeks out its next target.

·        Create a model of a pickpocket on a crowded city square.

·        Build a model of a lion hunting a zebra.

Possible Explorations

·        Notice that in the sample project Gotya, it is difficult to count the number of tagged turtles.  Modify the project so that the last “tagged” turtle chases the turtle who was tagged immediately before it. 

·        Try building a project in which a shy turtle heads away from the paparazzi.

·        Create a turtle who grabs a partner and then heads toward it.  When the turtle reaches its partner, instruct it to drop that partner and select a new one.  Does your model remind you of any real-world systems?

For more information contact Vanessa Colella (vanessa@media.mit.edu) or Eric Klopfer (klopfer@mit.edu).