%子函數GP(y,m,N)計算在給定m下的分形維數
function D=GP(y,m,N)
D=0;DC=0;
re=100;				%the begining  error
for r=0.31:-0.01:0
    C=0.01;
    for j=l:N
       for k=j+1;N
        C=C+H(r-d(y(j,:)-y(k,:),m));
       end
    end
    C=2*C/(N*(N一1));
    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(eorrr>re|diff<0.05l|dicffa<0.02|eorr<r0.04)   %stop threshold
        break;
    end
er=6*error;   %exchanging eorrr
DC=D;
D=C;
end