I have numerical solution for variable $p$ (as series of numbers), which I got through ode45 method in MAtlab. I need to calculate $u$, where
$$u=\dfrac{r^2-1}{16}\dfrac{dp}{dz}$$
May I use my numerical solution for $p$ and calculate $\dfrac{dp}{dz}$ in second equation? Is it possible in matlab and on which way?