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

 function x = odd_index(M)
%Input M is a matrix
%Output x is a matrix contains elements of M having odd index
%Example:
%    M=randi(10,5,8) (random matrix of 5x8 range 1-10)
%    x=odd_index(M)
 [n m] = size(M); %size of matrix M is nxm
 x = M(1:2:n,1:2:m); %skipping row and column by 2 to skip even indexes.