function D=GP(m,N)
D=0;DC=0;
re=100;%the begining error
 for r=0.31:-0.005:0
      C=0.01;
  for j=1:N
    for k=j+1:N
        C=C+H(r-d(y(j,:)-y(k,:),m));
      end
  end 
C=2*C/(N*(N-1)); 
C=log(C)/log(r);
error=abs(C-D)+abs(D-DC);
diffca=abs(((C-D)-(D-DC))/0.005);
diff=abs((C-D)/0.005)+abs((D-DC)/0.005);
     if(error>re|diff<O.O5l|diffca<0.02|error<0.04)
       %stop threshold
     end
 re=6*error; %exchanging error
   DC=D
 end