"index exceeds matrix dimension" error. generated when I try to implement APIT localization algorithm for wireless sensor networks. Please i need your help dear matlab users to fix this error..

function APIT(grid_length)   % Approximate Point In Triangle (APIT) Localization Algorithm
   load '../Deploy Nodes/coordinates.mat';
    load '../Topology Of WSN/neighbor.mat';
    %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    %all_nodes = anchor_nodes+unknown_nodes; 
    unknown_node_index = all_nodes.anchors_n+1:all_nodes.nodes_n;
    row_n=ceil(all_nodes.square_L/grid_length);col_n=row_n;
    centroid_x =((1:col_n)-0.5)*grid_length;
   centroid_y= ((1:row_n)-0.5)*grid_length;
    for i=unknown_node_index   
       disp([num2str(i)]);
        neighboring_anchor_index=find(neighbor_matrix(i,1:all_nodes.anchors_n)==1);
        neighboring_anchor_n=length(neighboring_anchor_index);
        if neighboring_anchor_n==3
           gridmap=zeros(row_n,col_n);
            grid_covered_flag=zeros(row_n,col_n);
            for a=1:neighboring_anchor_n-2
                for b=a+1:neighboring_anchor_n-1
                   for c=b+1:neighboring_anchor_n
                    neighboring_node_index=setdiff(find(neighbor_matrix(i,:)==1),neighboring_anchor_index([a b c]));

       perimeter(sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(2,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(2,2)).^2), sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(3,2)).^2), sqrt((neighboring_anchor_n(2,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(2,2)-neighboring_anchor_n(3,2)).^2));  % The error message shows "index exceeds matrix dimension" error happen in this line.   

                         if perimeter > rss                       Grid_in_triangle_abc=inpolygon(centroid_x,centroid_y,all_nodes.estimated(neighboring_anchor_index([a b c]),1),all_nodes.estimated(neighboring_anchor_index([a b c]),2));%Grid covered by triangles abc
                              gridmap=gridmap+Grid_in_triangle_abc;                            
                          end
                          grid_covered_flag=grid_covered_flag|Grid_in_triangle_abc;
                      end
                  end

             if any(any(grid_covered_flag))
                  weight_max=max(max(gridmap(grid_covered_flag)));            
                  weight_max_index=intersect(find(gridmap==weight_max),find(grid_covered_flag==1));
                  [weight_max_ind_row,weight_max_ind_col]=ind2sub(size(gridmap),weight_max_index);
                  all_nodes.estimated(i,:)=mean([weight_max_ind_col weight_max_ind_row;weight_max_ind_col weight_max_ind_row]*grid_length-0.5*grid_length);
                  all_nodes.anc_flag(i)=2;

              end

      save '../Localization Error/result.mat' all_nodes comm_r;

              end
          end

      end
  end

   Thank you very much in advance.

[Image Analyst]

kelil, here's a tip to format your code correctly. In MATLAB type control-a control-i to properly indent your code. Then copy it and paste it here. Highlight the code and then click the {}Code button. See this link

You forgot to attach your .mat files and forgot to tell us what you passed in for grid_length so we can't run your code. You also forgot to tell us the complete error so we don't know what line of code threw an error. Please read this link first then paste all the red text here, and attach the .mat files, so we can help you.

[Kelil Mohammed]

Thank you very much for your response and comments. Here I modify input argument but still after running few the same error occurred

function APIT(all_nodes) 

      load 'coordinates.mat';
      load 'neighbor.mat';

      %all_nodes = anchor_nodes+unknown_nodes; 

      disp('Longer time, wait patiently...');
      unknown_node_index = all_nodes.anchors_n+1:all_nodes.nodes_n;
      row_n=ceil(all_nodes.square_L); 
      col_n=row_n;
      centroid_x=repmat(([1:col_n]-0.5),row_n,1); 
      centroid_y=repmat(transpose([1:row_n]-0.5),1,col_n);
      for i=unknown_node_index   
         disp([num2str(i),':I am running, donot press it ...']);
          neighboring_anchor_index=find(neighbor_matrix(i,1:all_nodes.anchors_n)==1);
          neighboring_anchor_n=length(neighboring_anchor_index);
          if neighboring_anchor_n==3
              gridmap=zeros(row_n,col_n);
              grid_covered_flag=zeros(row_n,col_n);
             for a=1:neighboring_anchor_n-2
                 for b=a+1:neighboring_anchor_n-1
                      for c=b+1:neighboring_anchor_n
                          neighboring_node_index=setdiff(find(neighbor_matrix(i,:)==1),neighboring_anchor_index([a b c])); 

                      perimeter(sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(2,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(2,2)).^2), sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(3,2)).^2), sqrt((neighboring_anchor_n(2,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(2,2)-neighboring_anchor_n(3,2)).^2));   

                         if perimeter > rss

                              Grid_in_triangle_abc=inpolygon(centroid_x,centroid_y,all_nodes.estimated(neighboring_anchor_index([a b c]),1),all_nodes.estimated(neighboring_anchor_index([a b c]),2));%Grid covered by triangles abc
                              gridmap=gridmap+Grid_in_triangle_abc;                            
                          end
                          grid_covered_flag=grid_covered_flag|Grid_in_triangle_abc;
                      end
                  end

             if any(any(grid_covered_flag))
                  weight_max=max(max(gridmap(grid_covered_flag)));            
                  weight_max_index=intersect(find(gridmap==weight_max),find(grid_covered_flag==1));
                  [weight_max_ind_row,weight_max_ind_col]=ind2sub(size(gridmap),weight_max_index);
                  all_nodes.estimated(i,:)=mean([weight_max_ind_col weight_max_ind_row;weight_max_ind_col weight_max_ind_row]*grid_length-0.5*grid_length);
                  all_nodes.anc_flag(i)=2;

             end
               end
          end
      end
  end

The errors generated as follows:

Index exceeds matrix dimensions.

Error in APIT (line 30)
                    perimeter(sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(2,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(2,2)).^2),
                    sqrt((neighboring_anchor_n(1,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(3,2)).^2),
                    sqrt((neighboring_anchor_n(2,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(2,2)-neighboring_anchor_n(3,2)).^2));

Here are my mat files.