视频

拓展学习

股票预测问题

>> x=[2,3,4,5,8,9,10,11,12,15,16,17,18,19,22,23,24,25,26,29,30];

>> y=[7.74,7.84,7.82,7.78,7.91,7.97,7.9,7.76,7.9,8.04,8.06,8.11,8.08,8.13,8.03,8.01,8.06,8.0,8.3,8.41,8.28];

>> plot(x,y, '*');

>> p=polyfit(x,y,3);

>> plot(x,y,'*',x,polyval(p,x));

>> x1=[31,32,33];

>> xi=[x,x1];

>> plot(x,y,'*',xi,polyval(p,xi));

>> y1=[8.27,8.17,9.54];

>> plot(x,y,'*',xi,polyval(p,xi),x1,y1,'rp');

算法的参数优化问题

x=0.03:0.03:0.3;

y1=[0.01,0.01,0.02,0.03,0.06,0.07,0.13,0.17,0.25,0.37];

y2=[0.85,0.76,0.68,0.62,0.56,0.52,0.49,0.46,0.43,0.39];

plot(x,y1,'*',x,y2,'o');

p1=polyfit(x,y1,2);

p2=polyfit(x,y2,2);

p=p1-p2;

xi=roots(p);

xj=0:0.03:0.36;

yj1=polyval(p1,xj);

yj2=polyval(p2,xj);

yi=polyval(p1,xi(2))

plot(x,y1,'*',x,y2,'o',xj,yj1,xj,yj2,xi(2),yi,'rp');