Undefined function 'plus' for input arguments of type 'cell'.

Helllo

I'm running the following code, when I don't enter values it works fine and returns the default values. but when I enter inputs (i.e main(2,3)), It gives me the following error: Undefined function 'plus' for input arguments of type 'cell'.It points to the last statement. Thanks in advance.

function out = main (varargin)
switch nargin
    case 0 
        disp('no inputs entered');
        a=1; % default values
        b=1;
    case 1 
        disp ('one input intered')
        a= varargin(1);
        b=1;
    case 2 
        disp('two input entered ')
        a=varargin(1);
        b= varargin(2);
    otherwise 
        error('maximum length is two for the input argument')
end 
out = a+b;

[Stephen23]

You need to learn the two different ways to index cell arrays:

• {} curly braces refer to the cell contents, whereas
• () parentheses refer to the cells themselves.

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

Answer 1

[TADA]

varargin is a cell array

when you index a cell array using parentheses you get a cell array back, i.e:

c = {1 2 3};
a = c(1)

a =

  1×1 cell array

    {[1]}
    

instead you need to use curly bracers to index varargin:

a= varargin{1};

or in your case, simply don't use varargin, and use two input arguments instead:

function out = main (a, b)
    switch nargin
        case 0 
            disp('no inputs entered');
            a=1; % default values
            b=1;
        case 1 
            disp ('one input intered');
            b=1;
        case 2 
            disp('two input entered ');
            
        % this otherwise statement is no longer necessary,
        % a builtin error will be thrown if too many arguments are sent to this function
        %otherwise 
        %    error('maximum length is two for the input argument')
    end 
    out = a+b;
end

[Akram Awad]

Thanks. It worked out

[Stephen23]

@Akram Awad: don't forget to accept TADA's answer.