How to show latex by override `disp` in classdef?

classdef Myclass
    properties
        R;
    end
    methods
        function obj = PointGroupElement(R)
            obj.R = R;
        end
        function  disp(obj)
            symMatrixStr = symmatrix('R(1/3,[0,0,1])');
            disp(symMatrixStr);
        end
    end
end

When I run this class in live editor, I expect return or show latex form R(1/3,[0,0,1]) rather that str 'R(1/3,[0,0,1])', and i also know, it will return latex form when i run symMatrixStr = symmatrix('R(1/3,[0,0,1])') in live editor. So, what should i do to override disp so that the class outputs the latex form?

Answer 1

[Ayush Anand]

I think there is a mistake in your class definition, as the class name and the constructor names are different in the snippet provided by you.

Fixing that gives me the result as expected; the returned form when the class is called from live script is latex itself, and not string:

classdef Myclass
    properties
        R;
    end
    methods
        function obj = Myclass(R) %Fixing the constructor name
            obj.R = R;
        end
        function disp(obj)
            symMatrixStr = symmatrix('R(1/3,[0,0,1])');
            disp(symMatrixStr);
        end
    end
end

[jia]

Thanks for your answer, the name of class error is just a typo.

I want to obatin the result:

g = Myclass('R');
g % output R(1/3,[0,0,1])

rather that

g = Myclass('R');
disp(g) % output R(1/3,[0,0,1])

Answer 2

[surya venu]

Hi,

To display the LaTeX form of a symbolic matrix when using the "disp" method in a class definition in MATLAB, you need to ensure that the symbolic matrix is properly created and displayed. And I see that there's mismatch of class name and constructor.

Here is an example MATLAB code:

classdef Myclass
    properties
        R;
    end
    methods
        function obj = Myclass(R)
            obj.R = R;
        end
        function disp(obj)
            symMatrix = sym(obj.R);
            % Convert the symbolic matrix to LaTeX format
            latexStr = latex(symMatrix);

            disp(['$$', latexStr, '$$']);
        end
    end
end

To create an instance of your class and display the matrix in LaTeX format:

R = [1/3, 0, 0; 0, 1/3, 0; 0, 0, 1];
obj = Myclass(R);
disp(obj);

When you run this in the MATLAB Live Editor, it should display the matrix R in LaTeX format.

To know more about the "sym" and "latex" function, check out the links below:

https://www.mathworks.com/help/symbolic/sym.html

https://www.mathworks.com/help/symbolic/sym.latex.html

Hope it helps.

Answer 3

[Rahul]

Hi Jia,

I could the reproduce the issue. According to the code shared, the output does come as a char 'R(1/3,[0,0,1])'. I understand that you require the output in latex formatting.

Here are some of the methods that can give your desired output.

Method 1

You can change the 'disp' function in the classdef 'Myclass' as follows:

function  disp(obj)
    symMatrixStr = symmatrix('R(1/3,[0,0,1])');
    
    % Addition of 'latex' function to obtain latex representation
    symMatrixStrLatex = latex(symMatrixStr);
    
    disp(symMatrixStrLatex);
end

This will give the desired latex output as: \mathrm{R(1/3,[0,0,1])}

You can refer to this link for more information regarding latex function: https://www.mathworks.com/help/releases/R2024a/symbolic/sym.latex.html?searchHighlight=latex&s_tid=doc_srchtitle

Method 2

You can run your existing code in the live editor. The output will not be of latex format. However, if you right-click on the output, you can leverage the option available stating 'copy as LaTex'. This will copy the output in latex formatting to your clipboard.

Hope this helps!