Using arguments with optional parameters and repeating parameters

function argumentTest(opt,repeat1)
    arguments (Input)
        opt.test1
        opt.test2
    end
    arguments(Input,Repeating)
        repeat1
    end
end

This code does not work in MATLAB 2023a. It gives me the error "Positional arguments must be defined before name-value arguments.", which is not a valid error. I would think this is possible since opt in this example would not require an actual placement, but could be thrown anywhere in the function arguments. I think it has to do with exactly that, however. The placement of the optional argument could be in the place of a repeating argument, thus there is no way for it to know it is going on internally.

Answer 1

[Pratyush]

Hi @Brandon,

I understant you get a error "Positional arguments must be defined before name-value arguments." for your function. In MATLAB, the error "Positional arguments must be defined before name-value arguments" occurs when you try to define positional arguments (arguments without a name-value pair) after name-value arguments (arguments with a name-value pair). Try swapping the parameters to the function, replace your function signature with:

function argumentTest(repeat1, opt)

This should resolve the error.

[Brandon]

Interesting. If I wanted all types of input arguments, then I have to split the input arguments into two parts.

function argumentTest(nonopt,repeat1,opt)
    arguments (Input)
        nonopt
    end
    arguments(Input,Repeating)
        repeat1
    end
    arguments (Input)
        opt.test1
        opt.test2
    end
end

Thank you for the help!