what @ does in MATLAB?

I have a class name VI_Lecroy.

function obj = VI_SDA6000(varargin)
    obj = obj@VI_LeCroy(varargin{:});
end

What this @ does?

[Luca Ferro]

i think it is a function handle but i might be mistaken

[Walter Roberson]

@Luca Ferro

@ in other contexts is used for function handles, but in the context of being in the middle of a pair of words, is a superclass reference.

Answer 1

[chicken vector]

In this case @ is used to call a superclass method from a subclass.

Consider the classes Food and Donut, such that Donut is a subclass of Food.

If Food has a method eat, you can call this method from the subclass Donut using the operator @:

%% Food class:

classdef Food
    methods
        % Constructor
        function obj = Food(varargin)
            ...
        end
        
        function eatenFood = eat(varargin)
            ...
        end
    end
end

%% Donut class:

classdef Donut < Food
    methods
        % Constructor
        function obj = Donut(varargin)
            ...
        end
        
        function eatenDonut = eat(varargin)
            eatenDonut = eat@Food(varargin)
        end
    end
end

In particular, obj@Food calls the constructor method that is used to define class instances.

This is the method that has the same name of the class itself.

It follows that:

function obj = VI_SDA6000(varargin)
    obj = obj@VI_LeCroy(varargin{:});
end

implies that the instances of the class VI_SDA6000 are constructed in the same way as done in VI_LeCroy.

You can find more detailes here.

[Adam Danz]

Another good reference to add to @chicken vector's answer:

MATLAB Operators and Special Characters