b值小于0.6为很好的买点，股票可能在此筑底 可耐心持有
参数：N1=125，N2=5，N3=20
aa:=COUNT(C>=REF(C,1),N1)/COUNT(C<REF(C,1),N1);
b:MA(aa,N2);
d:MA(aa,N3)
