How I can correct this error? "Undefined operator '/' for input arguments of type 'function_handle'."

I'm trying to solve system of non-linear equation using Newton raphson method.

I'm coded right, but it keep me saying "Undefined operator '/' for input arguments of type 'function_handle'."

Any one can help me with it? The error is on line 19.

Heres the full code:

This code used to generate Jacobian vector.

function J=Derivative(F,x,xi,i)
e=0.001;
x1=x;
x2=x;
x1(i)=xi;
x2(i)=xi+e;
J=(F(x2)-F(x1))/e;
end

This is the full code I,m try to solve. In this code I have 8 system of equation, which are 5 of them are non-linear and 3 of them are linear.

%newton raphson method
clc
clear all
R=0.314;
T=1000;
z=@(x) x(1)+x(2)+x(3)+x(4)+x(5);
F1=@(x) 19720+(R*T*log(x(1)/z))-x(6)-4*x(7);
F2=@(x) -1920420+(R*T*log(x(2)/z))-2*x(7)-x(8);
F3=@(x) -200240+(R*T*log(x(3)/z))-x(6)-x(8);
F4=@(x) -395790+(R*T*log(x(4)/z))-x(6)-2*x(8);
F5=@(x) (R*T*log(x(2)/z))-2*x(7);
F6=@(x) x(1)+x(3)+x(4)-2;
F7=@(x) 4*x(1)+2*x(2)+2*x(5)-14;
F8=@(x) x(2)+x(3)+2*x(4)-3;
x=[0.25; 0.198; 0.222; 0.78; 0.7892; 2000; 3000; 5000];

for i=1:10
    F = [F1(x);F2(x);F3(x);F4(x);F5(x);F6(x);F7(x);F8(x)];   %The error is on this line
    for k=nume1(x)
        for j=numel(x)
            Jacobian(k,j)=Derivative(eval(['F' num2str(k)]),x,x(j),j);
        end
    end
    x=x-inv(Jacobian)*F;
end

[madhan ravi]

there's already an inbuilt function named as jacobian() , you have spelling error in j = nume1() should be numel() , after defining z , replace the other z's with z(x).

[tolossa kebede]

Thank you for your help madhan ravi, it's working.

Answer 1

[Steven Lord]

z=@(x) x(1)+x(2)+x(3)+x(4)+x(5);
F1=@(x) 19720+(R*T*log(x(1)/z))-x(6)-4*x(7);

You can't divide x(1) by the function handle z.

You could divide x(1) by the value obtained by evaluating the function handle z at x.

s = @sin;
c = @cos;
t1 = @(x) s(x)./c(x); % will work
t2 = @(x) s./c; % will fail when called

t1(2)-tan(2)
t2(2) % error

[tolossa kebede]

I understand my error, thank you steven.