Difference between two iteration of for loop

Hi I need to have difference between to successive iteration of for loop. As example:

For i=1:n P(i)=statement; end

How can I calculate: DeltaP=P(i)-P(i-1)??!! THANKS

Answer 1

[Adam]

diff( P )

after the for loop should do this for you for all pairs of consecutive elements of P

[Nasser Hasani]

Thanks for your answer