For MATLAB code.

2. Write a function called even_index that takes a matrix, M, as input argument and returns a matrix that contains only those elements of M that are in even rows and columns. In other words, it would return the elements of M at indices (2,2), (2,4), (2,6),, 4,2), (4,4), (4,6),., etc. Note that both the row and the column of an element must be even to be included in the output. The following would not be returned: (1,1), (2,1), (1,2) because either the row or the column or both are odd. As an example, if M were a 5-by-8 matrix, then the output must be 2-by-4 because the function omits rows 1, 3 and 5 of M and it also omits columns 1, 3, 5, and 7 of M