Optional Arguments in Function as Struct Input

I have a Matlab function with many optional arguments which I want to call with these arguments recursively... This is just a short example, my real code is much more complexe and I don't want to share it here... I know that this function seems kind of nonesense.

function [out] = calculateHatches(vec, args)
    arguments
        vec
        args.Limit = 0
        args.Color = 'red'
        args.Time = '12:00'
    % (and many more argumnts)
    end
    
    % some calculations that give me out

    out = []
    if args.Limit==0
        for i=1:10
            nargs = args;
            nargs.Limit = 1;
            % n arguments might change here ...
            % calculateHatches(vec,'Limit',nargs.Limit,'Color',nargs.Color,'Time',nargs.Time)
            nout = calculateHatches(vec,nargs)
    
            out = [out, nout]
        end
    end
end

However, this won't work, is there a way to makt it work?

calculateHatches(vec,nargs)

But I have too many optional arguments that change over time of programming too much, that I don't want to write it into the code. This would mean a lot of administration work.

calculateHatches(vec,'Limit',nargs.Limit,'Color',nargs.Color,'Time',nargs.Time)

Answer 1

[Steven Lord]

Use the namedargs2cell function.

[Ingo Hermann]

This function is splitting the arguments into cells, but I still cannot give it as input argument to calculateHatches like this. However, I can use eval to make it work somehow but this is not really nice ^^...

calculateHatches(vec,namedargs2cell(nargs))

Invalid argument at position 2. Function requires exactly 1 positional input(s).

% Fix using eval:

strVal = ['[out] = calculateHatches(vec'];

allArgs = namedargs2cell(nargs);

for i=1:2:size(allArgs,2)

strVal = [strVal,',"',char(allArgs{i}),'"',',allArgs{',char(num2str(i+1)),'}'];

end

strVal = [strVal,' );'];

eval(strVal);

[Stephen23]

"However, I can use eval to make it work somehow but this is not really nice ^^..."

EVAL is the opposite of nice. The MATLAB approach is to use a comma-separated list:

https://www.mathworks.com/matlabcentral/discussions/tips/847976-tutorial-comma-separated-lists-and-how-to-use-them

tmp = namedargs2cell(nargs);
out = calculateHatches(vec,tmp{:});

[Ingo Hermann]

Thank you, that was what I was looking for!