MATLAB Programming Fundamentals - MathWorks

Initialize Properties and Setup One-Time Calculations

This example shows how to write code to initialize and set up a System object.

In this example, you allocate file resources by opening the file so the System object can

write to that file. You do these initialization tasks one time during setup, rather than every

time you run the object.

Define Public Properties to Initialize

In this example, you define the public Filename property and specify the value of that

property as the nontunable character vector, default.bin. Users cannot change

nontunable properties after the setup method has been called.

properties (Nontunable)

Filename = "default.bin"

end

Define Private Properties to Initialize

Users cannot access private properties directly, but only through methods of the System

object. In this example, you define the pFileID property as a private property. You also

define this property as hidden to indicate it is an internal property that never displays to

the user.

properties (Hidden,Access = private)

pFileID;

end

Define Setup

You use the setupImpl method to perform setup and initialization tasks. You should

include code in the setupImpl method that you want to execute one time only. The

setupImpl method is called once the first time you run the object. In this example, you

allocate file resources by opening the file for writing binary data.

methods

function setupImpl(obj)

obj.pFileID = fopen(obj.Filename,"wb");

if obj.pFileID < 0

error("Opening the file failed");

end

end

end

Initialize Properties and Setup One-Time Calculations