[m,n]=hist(error);
hist(error)
for i = 1:length(m)
    text(n(i),m(i),strcat(num2str(roundn(100*m(i)/sum(m),-1),'%g'),'%'),...
    'HorizontalAlignment','center',...
    'VerticalAlignment','bottom')
end
set(gca, 'XTick', roundn(n,-3))
xlabel('Error')
ylabel('频数')
title('MiddleError')