How do I combine these answers into a matrix?

Here is the code I have.

A=[1;13;15;20;23;27];
for k=2:6;
    [index_diff]=A(k,1)-A(k-1,1)
end

I would like to put the answers (12,2,5,3,4) into a 5 by 1 matrix. How do I do this?

Answer 1

[Adam]

diff(A)

will do this.

[Catherine Mohs]

Got it! Thank you!

[Andrei Bobrov]

A=[1;13;15;20;23;27];
n = numel(A)-1;
index_diff = zeros(n,1);
for k=1:n;
    index_diff(k) = A(k+1)-A(k);
end

[madhan ravi]

A(2:end)-A(1:end-1)