Cannot figure out what went wrong

Hi all, I am actually using Octave, but it is similar to Matlab so I figure I should get it a shoot here. I have a problem while trying to do numerical solution. I got the following error while trying to run the script.

When I tried to remove the ";" I will get the following error.

I also noticed that there is nothing in the workspace. The weird part is that the code works just fine on my friend's Octave. I just copy and paste the code into my computer, but it does not run the script. Can anyone please help?

[KSSV]

Copy the code here...not image.....image snippet is not going to hlep any manner for checking.

[Daniel Yip]

z = 25;

l = 2500;

L0 = (z^2+l^2)^.5;

ks = 1.35;

EA = 50000000;

F_ext = 200;

v = [0:0.1:70]';

f_ext = EA*(L0-((z-v).^2+l^2).^0.5)/L0.*(z-v)/(((z-vI(i))^2+l^2)^0.5)+ks*v;

plot(v,f_ext); xlabel('v (mm)'); ylabel('f_e_x_t (N)');

vI = 0;

fI_ext = 0;

n = 50;

DF = F_ext/n;

Ki = [];

Dvi = [];

for i = 1 : n

 Li = ((z-vI(i))^2+l^2)^0.5;

 K = EA/L0 * ( (Li-L0)/Li+((z-vI(i))^2/(Li^2)) + ks;

 Dv = K^-1*DF;

 vI(i+1) = vI(i)+Dv;

 fI_ext(i+1) = fI_ext(i)+DF;

 Ki = [Ki;K];

 Dvi = [Dvi;Dv];

end

hold on; plot(vI,fI_ext,'o--')

[madhan ravi]

@Daniel check Steven's answer

Answer 1

[Steven Lord]

Count your parentheses.

[madhan ravi]

+1 @steven scrutinised precisely.

[madhan ravi]

z = 25;
l = 2500;
L0 = (z^2+l^2)^.5;
ks = 1.35;
EA = 50000000;
F_ext = 200;
v = [0:0.1:70]';
% f_ext = EA*(L0-((z-v).^2+l^2).^0.5)/L0.*(z-v)/(((z-vI(i))^2+l^2)^0.5)+ks*v; error was here also because you can't subtract scalar with vector
% 
% plot(v,f_ext); xlabel('v (mm)'); ylabel('f_e_x_t (N)');
vI = 0;
fI_ext = 0;
n = 50;
DF = F_ext/n;
Ki = [];
Dvi = [];
for i = 1 : n
   Li = ((z-vI(i))^2+l^2)^0.5;
   K = EA/L0 * ( (Li-L0)/Li+((z-vI(i))^2/(Li^2))) + ks; %error here as steven said one closing parentheses was missing here
   Dv = K^-1*DF;
   vI(i+1) = vI(i)+Dv;
   fI_ext(i+1) = fI_ext(i)+DF;
   Ki = [Ki;K];
   Dvi = [Dvi;Dv];
  end
hold on; plot(vI,fI_ext,'o--')

Answer 2

[Daniel Yip]

Thank you, got it working