For your reference here are some examples we had worked out in class. If you are not familiar with matlab please read the following instruction on how to access these m-files:
1. download them somewhere on computer
2. start matlab (installed on most university computers)
3. copy and paste these m-files in matlab's "current directory"
4. type the name of a m-file(e.g.  type "matrix" for the file "matrix.m") in the command window to execute it. You can also double click on the m-files to see the command lines in detail and make any changes you want.

About the name: e.g. "ex1_2_3.m" is the third example of section 1.2