MATLAB Programming

Designing User Classes in MATLAB
Use the whos function to see what objects are in the MATLAB workspace.
whos
Name Size Bytes Class
p 1x1 156 polynom object
The display Method
MATLAB calls a method named display whenever an object is the result of a
statement that is not terminated by a semicolon. For example, creating the
variable a, which is a double, calls the MATLAB display method for doubles.
a = 5
a =
5
You should define a display method so MATLAB can display values on the
command line when referencing objects from your class. In many classes,
display can simply print the variable name, and then use the char converter
method to print the contents or value of the variable, since MATLAB displays
output as strings. You must define the char method to convert the object’s
data to a character string.
Examples of display Methods
See the following sections for examples of display methods:
• “The Polynom display Method” on page 9-30
• “The Asset display Method” on page 9-48
• “The Stock display Method” on page 9-57
• “The Portfolio display Method” on page 9-60
Accessing Object Data
You need to write methods for your class that provide access to an object’s
data. Accessor methods can use a variety of approaches, but all methods that
change object data always accept an object as an input argument and return a
new object with the data changed. This is necessary because MATLAB does
9-13