Subtracting specific places in vector using diff

Hi, I'm using the function diff to subtract elements in a vector. I read the docomentation and I don't think I get it well and hopefuly someone can explein it to me. can I use the diff function to subtrat between the enen places with the odd olace before it (x(2)-x(1),x(4)-x(3) and so on)? 1- is it possible? 2 - what does diff(X,n) does exactly? thanks

Answer 1

[Matt J]

1- Not with |diff(). If you wanted to do that, it would be

x(2:2:end)-x(1:2:end)

2. diff(X,n) approsimates the n-th derivative of X using finite differences.

[sani]

thanks:)