y = @(x)log(x);

% Ask user for input values for h and M
% M denotes the number of steps of the algorithm.

h       = input('Input value h: ');
M       = input('Input value M: ');

%Initialize an MxM matrix
D = zeros(M);

disp(phi) = (1/(2*h)) * (y(x+h) - y(x-h));





Input value h: 1
Input value M: 2
Undefined function or variable 'x'.