Number Model Review II

Definitions: people coordinates are coordinates where (0,0) refers to the origin where the axes cross and positive y numbers are above the x-axis. Computer coordinates have (0,0) in the upper left corner and positive y means “down”.

1. You are making a viewing window that ranges from x=-300 to x=500 and from y=-200 to y=600.

2. Write three check-expects for the function x-people, which takes in a computer x-coordinate and produces a “people” x-coordinate.

3. Write three check-expects for the function y-computer, which takes in a people y-coordinate and produces a “computer” y-coordinate.

4. Write the functions x-people and y-computer. Make sure they pass your tests.

5. Write the functions x-computer and y-people that are the inverse of x-people and y-computer, just in case you need them… be sure to test.

6. Make a model t goes from 0 to 628 repeatedly. You will need to write a draw handler and a tick handler. The equations below give the x and y people coordinates to use to place the model.

        x-people-func = (* 250 (cos (/ t 100)))
        y-people-func = (* 150 (sin (/ t 100)))
   

Information Flow

This program works a little differently from the previous one. Keep in mind what information you have in your model and what you need in order to plot the result.