Spring 2001 CS100M    Exercise E7: Box Scope Diagrams   due in lecture Thu 3/01

suppose we have the following two functions defined:

file f.m

+-----------------------------------------------------+
| function [x,y] = f(a,b)                             |
|     % draw a picture whenever this line is reached! |
|     x = b-a;                                        |
|     y = a;                                          |
|     % draw a picture whenever this line is reached! |
+-----------------------------------------------------+

file g.m

+-----------------------------------------------------+
| function x = g(a,b)                                 |
|     % draw a picture whenever this line is reached! |
|     a = 2*a;                                        |
|     b = 2*b;                                        |
|     [a,b] = f(b,a);                                 |
|     a = 2*a;                                        |
|     b = 3*b;                                        |
|     x = a-b;                                        |
|     % draw a picture whenever this line is reached! |
+-----------------------------------------------------+

and suppose the following code is executed in the Command Window:

    a = 10; b = 20; x = 30;
    % draw a picture whenever this line is reached!
    x = g(15, 6);
    % draw a picture whenever this line is reached!

draw the 6 box scope diagrams requested:
+ trace the code by hand
+ whenever you reach a line $% draw a picture...$,
  draw a fresh copy of the box scope diagram in your answer

you may use the $boxscope$ code to generate a text picture for printing,
but make sure you can do the tracing by hand: we often have a tracing
question on exams.
_______________________________________________________________________________

Submission:

+ submit hard-copy (printed out or handwritten) in lecture.
+ remember to include your name, netid, cuid, exercise#, date.