How would I write this command?

Write MATLAB commands that computes the maximum prime number in a matrix.

I tried

function MaxPrime = MaxPrime(A)
MaxPrime = max(isprime(A));
disp(MaxPrime) 
end

got an error because one of my integers was negative. please help

[the cyclist]

This seems like homework. If you show us what you have tried so far, and ask a specific question, we can give you a hint. That is a good way to learn.

If you have no idea at all on how to get started, I suggest asking your instructor for help.

[David Hill]

primes cannot be negative by my definition, but if you wanted to ignore the negative, then

max(A(isprime(abs(A))));

[Ryan Williams]

Appreciate the help!