convert cell to vector that contains a function

hello,

i´m about to write a script that automatically computes some differential operatores for a given coordinate system.

" clear;

 syms r phi z;

 %Dimension N of coordinate system

 N = 3;

 x = cell(1,N);

 x{1} =  r * cos(phi);
 x{2} =  r * sin(phi);
 x{3} =  z;

 %new variables

 y(1) = r;
 y(2) = phi;
 y(3) = z;

 %tangential vectors ta

 for i = 1:1:N
   for j = 1:1:N
    ta{i,j} = diff(x{i},y(j));
   end
 end

 %show content

 celldisp(ta);
"

now i want to save the content of ta{:,1} into a vector tmp and than compute the 2-norm of this vector...

i already tried something like this: "

      tmp = ta{1,:};
      b{1} = Norm(tmp,2);

"

but with this i get the following error " Undefined function 'Norm' for input arguments of type 'sym'."

thanks a lot for your time thanks for your time

Answer 1

[Andrei Bobrov]

syms r phi z;
x =  [r * cos(phi); r * sin(phi); z];
%new variables
y = [r; phi; z];
ta = jacobian(x,y);
b0 = arrayfun(@(ii)norm(ta(ii,:)),(1:size(ta,1))','un',0);
b = cat(1,b0{:});