how to fix error "index exceeds matrix dimension"?" from 60 by 2 matrix I want to calculate perimeter of ABC formed by three anchor nodes in WSN.I got error message 'index exceeds matrix dimension' .

function perim = perimeter(AB,AC,BC) perim = AB+AC+BC;

     if neighboring_anchor_n>=3
            gridmap=zeros(row_n,col_n);
            grid_covered_flag=zeros(row_n,col_n);                   
   perim =sqrt(transpose((neighboring_anchor_n(1,1)-neighboring_anchor_n(2,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(2,2)).^2)+sqrt(transpose((neighboring_anchor_n(1,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(1,2)-neighboring_anchor_n(3,2)).^2)+sqrt(transpose((neighboring_anchor_n(2,1)-neighboring_anchor_n(3,1)).^2+(neighboring_anchor_n(2,2)-neighboring_anchor_n(3,2)).^2);          

     end 
  end