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Methods That Modify Default Behavior

How to Customize Class Behavior

There are functions that MATLAB® calls implicitly when you perform certain actions with objects. For example, a statement like [B(1);A(3)] involves indexed reference and vertical concatenation.

You can change how user-defined objects behave by defining methods that control specific behaviors. To change a behavior, implement the appropriate method with the name and signature of the MATLAB function.

Which Methods Control Which Behaviors

The following table lists the methods to implement for your class and describes the behaviors that they control.

Class Method to Implement


Concatenating Objects

cat, horzcat, and vertcat

Customize behavior when concatenating objects

See Subclasses of Built-In Types with Properties.

Creating Empty Arrays


Create empty arrays of the specified class.

Displaying Objects



MATLAB calls display when an expression or statement is not terminated by a semicolon. This displays the result and any relevant variable names.

disp(E) displays only the result of the expression. Overloading disp is one way to customize how your objects are displayed.

See Overloading the disp Function.

Converting Objects to Other Classes

converters like double and char

Convert an object to a MATLAB built-in class

See The Character Converter and The Double Converter.

Saving and Loading Objects

loadobj and saveobj

Customize behavior when loading and saving objects

See Object Save and Load.

Reshape and Rearrange


Rearrange dimensions of N-D array


Transpose vector or matrix


Complex conjugate transpose


Reshape array


Replicate array along specified dimensions

Determine Size and Shape


Determine if the input is a scalar


Determine if the input is a vector


Determine if the input is a matrix


Determine if the input is empty

Overload Functions and Override Methods

Overloading and overriding are terms that describe techniques for customizing class behavior. Here is how we use these terms in MATLAB.


Overloading means that there is more than one function or method having the same name within the same scope. MATLAB dispatches to a particular function or method based on the dominant argument. For example, the timeseries class overloads the MATLAB plot function. When you call plot with a timeseries object as an input argument, MATLAB calls the timeseries class method named plot.

To call the nonoverloaded function, use the builtin function.


Overriding means redefining a method inherited from a superclass. MATLAB dispatches to the most specific version of the method. That is, if the dominant argument is an object of the subclass, then MATLAB calls the subclass method.

To control class dominance, use the InferiorClasses attribute.

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