Fixed-Point Code for MATLAB Classes - MATLAB & Simulink (original) (raw)

Main Content

Automated Conversion Support for MATLAB Classes

The automated fixed-point conversion process:

• Proposes fixed-point data types based on simulation ranges for MATLAB® classes. It does not propose data types based on derived ranges for MATLAB classes.
• Supports class methods, properties, and specializations. For each specialization of a class, class_name, the conversion generates a separate class_name_fixpt.m file. For every instantiation of a class, the generated fixed-point code contains a call to the constructor of the appropriate specialization.
• Supports classes that have get and set methods such as get.PropertyName, set.PropertyName. These methods are called when properties are read or assigned. The set methods can be specialized. Sometimes, in the generated fixed-point code, assignment statements are transformed to function calls.

Unsupported Constructs

The automated conversion process does not support:

• Class inheritance.
• Namespaces.
• Constructors that use nargin and varargin.

Coding Style Best Practices

When you write MATLAB code that uses MATLAB classes:

• Initialize properties in the class constructor.
• Replace constant properties with static methods.

For example, consider the counter class.

classdef Counter < handle properties Value = 0; end

properties(Constant) MAX_VALUE = 128 end

methods function out = next(this) out = this.Value; if this.Value == this.MAX_VALUE this.Value = 0; else this.Value = this.Value + 1; end end end end

To use the automated fixed-point conversion process, rewrite the class to have a static class that initializes the constant property MAX_VALUE and a constructor that initializes the propertyValue.

classdef Counter < handle properties Value; end

methods(Static) function t = MAX_VALUE() t = 128; end end

methods function this = Counter() this.Value = 0; end function out = next(this) out = this.Value; if this.Value == this.MAX_VALUE this.Value = 0; else this.Value = this.Value + 1; end end end end