x=[20,22,24,26,28,30,32,34,36,38,40,42,44];
y=[62.9,68.8,71.2,82.5,84.1,88.6,88.4,88.4,88.0,88.0,88.0,88.0,88.0];
plot(x,y,'-r*');
xlabel('Number of Gabor features');
ylabel('classification recognition rate (%)');
legend('pain vs.non-pain','location','northwest');
xlim([20, 45]);
ylim([60, 90]);
set(gca,'XTick',[20:2:45]) %改变x轴坐标间隔显示 这里间隔为2
axis([10,50,50,100]) % axis([xmin,xmax,ymin,ymax])用这个语句调整坐标轴数字显示