The help of TABULATE states: If the elements of X are non-negative integers, then the output includes 0 counts for any integers that are between 1 and max(X) but do not appear in X.
I do not know the reason behind this behaviour, but it does suggest the following solution: 1. add a negative value to the input 2. remove this entry after tabulation
A = [5 5 7 10 10 10]
B = tabulate([A(:) ; -Inf])
B = B(2:end,:)
