Consecutive subtraction of the entries of a vector

I am a novist in MATLAB. I have no idea of how to subtract the entries of a vector consecutively. Say if A=[3,5,9,11,15]' and I want something like this B =[3, 2, 4, 2, 4]. Any help will do, thanks in advance.

Answer 1

[James Tursa]

If A is a row vector:

B = [A(1) diff(A)];

If A is a column vector:

B = [A(1);diff(A)];

[Hmm!]

Thank you James. Based on your code, I tried find the division version but it seems matlab has no build in function for division. I would like to divide the consecutive entries of A to get something like this: A=[-, 5/3, 9/5, 11/9 ,15/9]' and I tried something like B = [A(1); A.\ A ] and that did not work. I would appreciate it if you can help. Thank you in advance.

[Hmm!]

A typo B = [A(1); A./ A]

[James Tursa]

B = [A(1);A(2:end)./A(1:end-1)];