have a problem when I execute my code. It keeps giving me the message (Index exceeds matrix dimensions.) I am including my code for reference. Any help would be appreciated. Thanks a lot

%x = zeros(n, 1);
%for i = 1:n
%x(i) = i * sin( i^2 *pi/n );
%end
% v is the vector of voltage 
% C is the current I
% CS is the current Is
T=3000;

vth=((1.3806503*10^-23)*300)/(1.602176527*10^-19);
%T = 3000;                  %%number of iterations
%t=1:T;
%e1 = 2*(rand(size(t))-0.5);     %% U(-1,1)
CS=1.919*10^-20;
rs=3.38;
rsh=3.105^10^9;
%C=zeros (51);
mu=1.0179;
for v=[1:0.85, 0.849, 0.849, 0.848, 0.848, 0.848, 0.82, 0.79, 0.76, 0.73, 0.7, 0.67, 0.64, 0.61, 0.58, 0.55, 0.52, 0.49, 0.46, 0.43, 0.4, 0.37, 0.34, 0.31, 0.28, 0.25, 0.22, 0.19, 0.16, 0.13, 0.1, 0.0701, 0.04, 0.01, -0.0199, -0.0499, -0.08, -0.11, -0.14, -0.17, -0.2, -0.23, -0.26, -0.29, -0.32, -0.35, -0.38, -0.41, -0.44, -0.47, -0.5]

     C=CS.*(exp((v-rs*C)/(mu*vth))-1) + (v-rs*C)/rsh;
  end
  %i
  subplot(2,2,2);
  plot(C(1,1:T-1));   
  xlabel('Voltage' );
  ylabel(' Current');
  title('Experimental data (dots) and numerical characteristic (line) ');

[Julian]

why is 1:0.85 in your for v=[1:0.85,...,..] thats trying to go from 1 to .85 by 1s but then you list off values? indexing messages normals means you are trying to pull one more number out then you have aviable. I.E in a 1 by 5 of [1,2,3,4,5 ] you are trying to use a 6 that isnt there. if my matlab hadnt died on me i

[Julian]

id try your code and give a better suggestio

[Gihan]

Thanks Julian

I have tried your suggestion , but with the same statement. Will you try to run it ?

[Fangjun Jiang]

Don't post duplicated questions!

Answer 1

[Walter Roberson]

The code you show cannot run. You do not initialize C anywhere, so it is not available to be used on the right hand of the assignment in the "for v" loop, so the code would crash.

If you were to remove the comment character and thus expose

C=zeros(51);

then that would initialize C to be a 51 x 51 array. Then after the "for v" loop, you attempt to access

C(1,1:T-1)

where T is 3000. There would, however, not be any element C(1,52) through C(1,2999) so the code would crash with a complaint about index exceeding matrix dimension.

Note: a 51x51 array only has 2601 total elements in it, so looking for the 2999th element if it is not going to work.

[Gihan]

Thanks Walter for you suggestions. However I tried them with no hope ! I need this file to work soon , so any help will be appreciated.

[Naz]

It would be better for you to post the actual problem that you are trying to solve. It's just difficult to understand what your script should do. Also, there could be a better approach to implement the code.