MATLAB: Function help – selects the even rows and columns and returns of matrix M and then puts them in a new matrix called even

Question

Hi,

I want to write a function in MATLAB that selects the even rows and columns and returns of matrix M and then puts them in a new matrix called even.

I am new to functions and I am not sure why I am getting the following error;

Not enough input arguments.
Error in even_index (line 2)

The code I am using is the following

function even = even_index(M)
    even = M(2:2:end,2:2:end);
end

Thanks

Answer 1

You didn't pass any argument to the function when you called it -- hence there was nothing inside the function for M

M=rand(5);
even=even_index(M);

will work...