Can someone help me with symbolic differentiation?

Hi,

I'm trying to differentiate a vector of fuctions in order to a vector of variables and I keep getting the error:

??? Undefined function or method 'Diff' for input arguments of type 'sym'.

My code is:

NVar=4;
NConstr=2;

syms x y z w;

Var=[x y z w];
Phi=[x+y+z+w;x*y+z^2+w^3*z];

for i=1:NConstr

      for j=1:NVar

          TempVar2=Diff(Phi(i,1),Var(j));

      end

end

The purpose of this code is to aplly it to my master thesis, where I need to differentiate a (47X1) constraint vector in order to a vector of coordinates that is (102X1). Can anyone help me?

Best regards,

Paulo

Answer 1

[Wayne King]

The immediate cause of your problem is that MATLAB is case-sensitive and you want to use diff(), not Diff()

Answer 2

[Andrei Bobrov]

TempVar2 = jacobian(Phi,Var);

Answer 3

[Paulo Francisco]

Thank you both, it's working now.

Paulo