matlab做出線性回歸圖形

 x=[1656,2122,2864,4033,6099];
 y=[2112,2170,2291,2456,2759];
 [P,S]=polyfit(x,y,1)
%P為擬合回歸系數即y=P(1)*x+p(2)
P =1.0e+003 *0.0001 1.8666
S =
R: [2x2 double]
df: 3
normr: 9.4223

>> [Y,delta]=polyconf(P,x,S)
%給出回歸Y的95%的置信區間為[Y-delta，Y+delta]
Y =
1.0e+003 *

2.1090 2.1772 2.2858 2.4569 2.7592
delta =

20.6907 19.8923 19.1147 19.2502 23.2005
>> x1=1600:100:6100;
>> f=polyval(P,x1);
>> plot(x,y,'ro',x1,f,'-')%繪圖查看擬合效果
>> hold on
>> plot(x,Y+delta,'*g')
>> plot(x,Y-delta,'*g')%給出擬合的置信區間