how to make a comparison in a for loop. Problem on indexes

At the end of the for loop l want to compare the values of I(i) and I(j) look at the second for loop. here is the returned error :

??? Attempted to access I(2); index out of bounds because numel(I)=1.

Error in ==> eliminationphase at 143
              if (I(i)==I(j)&&(j < i))

Look at the code below:

     alpha= 10;

         I=1;
           for i=1:N
            if (~ismember(num2str(i), num2str(F)))

                      while (C(i) < alpha) 
                            for j=1:N
                         if ((i~=j) && (ismember(j, neighbour_n{i})))

                             C(i)=C(i)+C(j);
                             display(['la somme des cardinaux de ', num2str(i), ' is   ', num2str(C(i))]);

                             I=I+1;

                              display(['The number of iteration of  ', num2str(i), ' is   ', num2str(I)]);

                         end 
                            end
                      end

                         if (~ismember(num2str(i), num2str(F)))
                          display(['the value of the node:  ', num2str(i), '   at the end of while is ;  ', num2str(C(i))]); 
                         end

           end

     end
    % how to compare betwwen I(i) and l(j)?
    % l need to retreive the all the values of I and compare between them and between thein indices

     for i=1:N
           for j=1:N
               if (((~ismember(num2str(i), num2str(F)))&&(~ismember(num2str(i), num2str(F))))&&(i~=j))
                  if (I(i)==I(j)&&(j < i))
                      display(i);
                  end 
                   if (I(i) >I(j))
                      display(i);
                   end 
               end
           end  
       end

[Geoff Hayes]

mazari - use the debugger and step through the code to see why I is just a scalar and never becomes an array. Given that you haven't indicated what N, F, or C (etc.) are then it becomes difficult for others to try to debug the problem.

The error message is clear on what the problem is - you are expecting I to be a matrix or an array and instead it is just a scalar. When you run the above code, do you ever see any of the output statements (those from the display calls)?

[mazari ahmed]

l have adjusted the first loop N=200; % the number of nodes F=deleted_node{i}; % the set of deleted nodes (i=1:N) C=lenght(neighbour_n{i}); %the number of neighbours of the node i. Yes Geoff l do agree with you l need I as a scalar.the idea is that each node i has its own value of I.to make a comparison of the values of I of different nodes l need to have the index for exemple I(1)=5 I(3)= 2 ...

l've changed the intruction I(i)=I(i)+1 by I=I+1 (in the first loop)and it works perfectly.But how can l compare the value of I(1) and I(2)... in the second loop ? I(i) and I(j)

[Geoff Hayes]

Why do you have the following condition in the inner for loop of your second loop block

 if (((~ismember(num2str(i), num2str(F)))&&(~ismember(num2str(i), num2str(F))))&&(i~=j))

What is the intent behind this code?

[mazari ahmed]

Finally you are right Geoff, it's working

Answer 1

[mazari ahmed]

Finally you are right Geoff, it's working