MATLAB: Prelocation of array entries

Question

Let's say I have the following array: A = [2 4 6 8] and I want array B to be populated according to the following pattern: (entry from A)-1, entry from A, (entry from A)+1 so in this case B = [1 2 3 3 4 5 5 6 7 7 8 9]

How do I do this?

Thanks

Answer 1

A = [2 4 6 8]  
B=cell2mat(arrayfun(@(x) [x-1 x x+1],A,'un',0))

%or

B=[A-1; A ;A+1]
B=B(:)'