How to set mutually exclusive arguments in matlab?

How to use the new "arguments" parameter qualifier to control mutually exclusive two(or more) parameters as function inputs?

for example:

function out = twoStats(x,y)
    arguments
        % If you have input x, you cannot input y
         % If you have input y, you cannot input x
    end
end

similar question:

"Two optional parameters mutually exclusive"

[Jon]

I have been looking through the documentation. It appears that the input validation only operates on a single argument at a time. I don't see any mechnisim for making the validation of one input dependent upon another, e.g. must be empty if b is not empty. Obviously you could check this yourself, but I understand that you want to use the new argument feature to do this

Answer 1

[Bruno Luong]

function out = twoStats(x,y)
    arguments
        x = [];
        y {MustBeExclusive(x,y)} = [];
    end
    % out = ...
end

function MustBeExclusive(varargin)
    if sum(cellfun('isempty',varargin)) ~= 1
        eid = 'XY:NotExclusive';
        msg = 'X and Y must be exclusive.';
        throwAsCaller(MException(eid,msg))
    end
end

[cui,xingxing]

By the way, how can I input the parameter y instead of x? For example, I only input y=3, but I cannot call this function. Is the input x or y?

function out = twoStats(x,y)
    arguments
        x = [];
        y {MustBeExclusive(x,y)} = [];
    end
    out = y; % assume 
end
function MustBeExclusive(varargin)
    if sum(cellfun('isempty',varargin)) ~= 1
        eid = 'XY:NotExclusive';
        msg = 'X and Y must be exclusive.';
        throwAsCaller(MException(eid,msg))
    end
end

out = twoStats(y=3) ？

--------------------

similar question:

How to input dependent parameters in matlab function?

[Steven Lord]

>> twoStats([], 5) % x is the "placeholder" empty []
ans =
     5

>> twoStats(1, []) % y is empty
ans =
     []

>> twoStats(1) % specify only x, let y take on its default value
ans =
     []

>> twoStats(1, 2) % neither is empty, this is not valid
Error using twoStats
Invalid argument at position 2. X and Y must be exclusive.

I would consider what the condition in MustBeExclusive should be carefully. If specifying both x and y as empties is allowed you should use == 0 instead of ~= 1. Should the following work? Currently it does not.

>> twoStats([], [])
Error using twoStats
Invalid argument at position 2. X and Y must be exclusive.

[cui,xingxing]

Thanks, great!