How to get good derivatives results in matlab?

Question

I got the set of some points, and I need to get derivatives from it. I try to use the diff() function in matlab but, well, results kinda not ok. Is there any better way how I can do that?

Answer 1

this is only an example, however, before you use the command diff, you have to declare the variable syms x and then derive with respect to x the function you wish :-)