Generate Code for MATLAB Handle Classes and System Objects

This example shows how to generate code for a user-defined System object™ and then view the generated code in the code generation report.

A System object is a subclass of the matlab.System handle class. To generate code for a general handle class, follow similar steps as in this example.

1. In a writable folder, create a System object, AddOne, which subclasses from matlab.System. Save the code as AddOne.m.

   classdef AddOne < matlab.System
   % ADDONE Compute an output value that increments the input by one
   
     methods (Access=protected)
       % stepImpl method is called by the step method
       function y = stepImpl(~,x)
         y = x+1;
       end
     end
   end	  

2. Write a function that uses this System object.

   function y = testAddOne(x)
   %#codegen
     p = AddOne();
     y = p.step(x);
   end    

3. Generate a MEX function for this code.

   codegen -report testAddOne -args {0}

   The -report option instructs codegen to generate a code generation report, even if no errors or warnings occur. The -args option specifies that the testAddOne function takes one scalar double input.

4. Click the View report link.

5. In the MATLAB Source pane, click testAddOne. To see information about the variables in testAddOne, click the Variables tab.

   

6. To view the class definition for addOne, in the MATLAB Source pane, click AddOne.