how can i calculate the nombre of neighbors of wsn

i want to deploy a wsn in 100*100 axes with n node and R radius i calculat a distance between all the node and between a sink(100,100)position; i want to calculte the nombre of neighbor (degree) for each node (i supose that distance(u,v)<R/2 to be neighbor(u,v))i supose that the range of sensor (r)is equal to 2* R(range of communication) so i want to wait until i have calculated the degree for every node and then once that has been completed, find (plot)that node with the maximum degree and minimum distance to the sink.) + the condition of dist<d<(handles.r) and save it in new matrix 2 .my code is :

net = [1:n;rand([1,n])*x;rand([1,n])*y];
net1 = net;
*************%
degree=[];
  if isfield(handles,'net')
    for i = 1:numel(handles.net(1,:))
        degree(i)=0;
    for j = 1:numel(handles.net(1,:))
        X1 = handles.net(2,i);
        Y1 = handles.net(3,i);
        X2 = handles.net(2,j);
        Y2 = handles.net(3,j);
        xSide = abs(X2-X1);
        ySide = abs(Y2-Y1);
        d = sqrt(xSide^2+ySide^2);% distance euclidienne
         DD(:,i)=d;
         %disp(DD);
         %RESORTIR LES NOEUD REDONDANTS
        if (d<(handles.r))&&(i~=j)
            degree(i)=degree(i)+1;% CALCULE LEs nombre de neighbord( DEGRE) DES NOEUDS REDONDANTS
            disp(degree(i))
   if (max(degree))%&&(min(handles.d_sink))
                        plot([X1,X2],[Y1,Y2],'o','LineWidth',0.1);
                        grid on;
                    end
                end
            end

[Walter Roberson]

What is the difference between this question and your earlier http://uk.mathworks.com/matlabcentral/answers/253736-degree-of-neighbor-in-wsn ?