Practice in MATLAB

• Practice problem 1: Edit buggy.m so that when it runs, it produces this output in the Command Window:
  

  >> buggy
  ans =
       3
  ans =
     120
  ans =
       5
  ans =
      57
  ans =
       2
  ans =
          3125
  Warning: Divide by zero.
  > In buggy at 13
  ans =
     Inf
  ans =
      3.1416
  ans =
    314.1593
  ans =
     3.1416e+03
  ans =
       0
  ans =
     71.3208
  Welcome to CS112
  >> 
  

• Practice problem 2: Create a new file called test.m. We're going to work with 3 different values:
  • 2π²
  • √2
  • (0.000001234 + 5.67 × 10^-3) × 0.4567 × 10^-4

  Write test.m so that it produces output exactly like this:
  

    >> test
  This is the start of my program
  ans =
     19.7392
  The square root of 2 is
  ans =
      1.4142
  ans =
     2.5901e-07
  The square root of 1010101 is 
     1.005e+03
  This is the end of my program
  >> 
  

  Note that you can change the format of the numbers by using format long to produce this output:
  

  >> test
  This is the start of my program
  ans =
    19.73920880217872
  The square root of 2 is
  ans =
     1.41421356237310
  ans =
       2.590052567800000e-07
  The square root of 1010101 is 
     1.005037810234023e+03 
  This is the end of my program
  

  **Challenge: Change the 'square root of 1010101' output in the box above (the 3rd to last line) so that the text and value are displayed on the same line like this:

   The square root of 1010101 is 1005.0378 

• Inserting disp statements in your code can help pinpoint the location of bugs in your scripts (you can always remove the excess disp statements after your code works perfectly).
• clc clears the Command Window, which some people like when running their code
• Fastest way to re-run a script? Double-click on the name of the script in the Command History window (if you like the mouse) or hit the "up-arrow" key (if you prefer the keyboard) to yank back the last command, and then hit return.
• A semicolon ; suppresses output. Try adding semicolons at the end of a few lines in your test.m. Run test.m and note the difference in the Command Window. (Today we are not producing a lot of output, but in the future, the semicolon will come in handy).