How can I use for loop twice

error: for | Error: Expression or statement is incomplete or incorrect.

 syms x
 Fun = (sqrt(7.447.*(200-x).*(2.0720.*x-200.*sqrt(9.01)+sqrt(9.01.*200^2- 7.9810*200.*x))))/8; 
 h=1; 
 zi = 1:360;
 x=0:h:200;
 Fun1 = matlabFunction(Fun);

    for i=1:(length(x)-1)
        for
            j=1:360
        end
    y1 = Fun1(x(i));
    z1 = Fun1(x(i));
    x2 = x(i)+h;
    y2 = Fun1(x(i+1));
    z2 = Fun1(x(i+1));
    x3 = x(i)+h;
    y3 = y2*cos((pi/180)*zi(j));
    z3 = z2*sin((pi/180)*zi(j));
    T1 = [0, y3-y2, z3-z2];
    T2 = [x(i)-x(i+1), y1-y2, z1-z2];

    Vec = cross(T1,T2);
    deltal = sqrt((y2-y1)^2+h^2);
    deltazi = sqrt(z3^2+(y2-y3)^2);
    dA11 = deltal.*deltazi;
    end

please help me

Answer 1

[Azzi Abdelmalek]

Look at this part of your code

for
    j=1:360
end

It's not correct, and even it's corrected

for j=1:360
end

This doesn't mean anything, maybe what you want is this:

syms x
Fun = (sqrt(7.447.*(200-x).*(2.0720.*x-200.*sqrt(9.01)+sqrt(9.01.*200^2- 7.9810*200.*x))))/8;
h=1;
zi = 1:360;
x=0:h:200;
Fun1 = matlabFunction(Fun);
for i=1:(length(x)-1)

    y1 = Fun1(x(i));
    z1 = Fun1(x(i));
    x2 = x(i)+h;
    y2 = Fun1(x(i+1));
    z2 = Fun1(x(i+1));
    x3 = x(i)+h;
    for   j=1:360
        y3 = y2*cos((pi/180)*zi(j));
        z3 = z2*sin((pi/180)*zi(j));
        T1 = [0, y3-y2, z3-z2];
        T2 = [x(i)-x(i+1), y1-y2, z1-z2];
        Vec = cross(T1,T2);
        deltal = sqrt((y2-y1)^2+h^2);
        deltazi = sqrt(z3^2+(y2-y3)^2);
        dA11 = deltal.*deltazi;
    end
end

Answer 2

[Mischa Kim]

Hi Omkar, looks like the second end is misplaced. Als, I recommend using ii instead of i (and same for j) because it is also used as the imaginary unit.

Fun1 = matlabFunction(Fun);
for i = 1:(length(x)-1) %%replace i by ii
    for j = 1:360       %%replace j by jj
        y1 = Fun1(x(i));
        z1 = Fun1(x(i));
        x2 = x(i)+h;
        y2 = Fun1(x(i+1));
        z2 = Fun1(x(i+1));
        x3 = x(i)+h;
        y3 = y2*cos((pi/180)*zi(j));
        z3 = z2*sin((pi/180)*zi(j));
        T1 = [0, y3-y2, z3-z2];
        T2 = [x(i)-x(i+1), y1-y2, z1-z2];
        Vec = cross(T1,T2);
        deltal = sqrt((y2-y1)^2+h^2);
        deltazi = sqrt(z3^2+(y2-y3)^2);
        dA11 = deltal.*deltazi;
    end
end