assessFunctionPresence use in Matlab Grader for checking one out of n functions are present

I am setting up a test in Matlab Grader to check that students use a for or a while loop in an exercise. They can only use one out of the two. The problem is that there is no way to set up an assessFunctionPresence test for this purpose. Is there any way around it?

Answer 1

[Cris LaPierre]

The MATLAB Code assessment type allows you to use any code you want to create an assessment. There are ways to achieve the result you want with assessFunctionPresence combined with assessFunctionAbsence, since it is the combination that is important. For example

try
    assessFunctionPresence('while')
    assessFunctionAbsence('for')

catch
    assessFunctionPresence('for')
    try
        assessFunctionAbsence('while')
    catch
        assert(false,'You must use either a for loop or a while loop, but not both')
    end
end

Any time a test evaluates false, you are bumped to the next level of the try/catch. If the solution contains both for and while loops, the assert statement will mark the answer false and give the student meaningful feedback on how to correct the code.

[Antonio Mele]

Thanks for your help.