How to find a symbolic derivative?

Question

Mike Meyers 2017-11-19

编辑： Mike Meyers 2017-11-19

Assume you are writing a complex function - in my case, to find the equations of motion of a coupled drives system (CE108).

Is there a way to differentiate a symbolic variable (say, x) so that you get its symbolic derivative (in our case, dx)?

Example:

 syms x, m
 T = 0.5*m*x^2
 y = SymbolicDerivative(T,x);  %is there something like this
 y = m*dx                      % that gives this?

Any custom made functions or any prebuilt ones you know?

Edit:

The function diff doesn't help, since it differentiates x to 1, while I am looking for something that instead derivates to dx

Answer 1

Star Strider 2017-11-19

See if the functionalDerivative (link) function does what you want. (It was introduced in R2015a.)