totalderivative(f,s)
Returns the total derivative of function f with respect to the argument name in variable s.
See also partial derivative divergence jacobian curl laplacian gradient
Example
f(x,y,t)=x*y*t
f(x,y,t)=x*y*t
T=totalderivative(f,"t")
T(x,y,x',y',t)=t*x'*y+t*x*y'+x*y