Lab 2

Collections of numbers, vector operations and 2D plots

Part 1. MATLAB Tips of the day

Tip #1: colon notation
The colon notation is very helpful when generating vectors: start:step:end
(step is optional)

   10:20 ==> [10 11 12 13 14 15 16 17 18 19 20]
   10:5:20 ==> [10 15 20]
   10:6:20 ==> [10 16]
   0:0.2:1 ==> [0 0.2 0.4 0.6 0.8 1.0]

Note that 0:0.2:1 is equivalent to colon(0, 0.2, 1)

Tip #2: ellipsis
If you happen to find yourself typing in a looooong MATLAB expression,
you can use an ellipsis (...) to indicate line continuation. For example,
code broken across lines with ellipsis
Problem: You cannot use ellipsis within a string, for example:
disp broken across lines with ellipsis
MATLAB often uses color to indicate how it understands your code.
See the red that turns into black and then purple above? That suggests a problem.

Solution? Break your statement up into separate disp commands, like this
(note that the code below is part of an m-file, rather than code typed directly into the command window):

separate disp statements

Tip #3: The input MATLAB command
Look it up in the online MATLAB documentation. Experiment with it in the command window.
  • How can you get a number back?
  • How about a string?
  • What if the user hits Return without having entered anything at all?
  • What happens if you add or omit the semicolon (;) at the end of the command?