matlab-最小二乘法拟合

Posted 2022-07-28 studyer_domi

1、内容简介

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2、内容说明

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3、仿真分析

close all
clear
clc
x=2:15;
y=[6.42,8.20,9.58,9.50,9.70,10.00,9.93,9.99,10.49,10.59,10.60,10.80,10.60,10.9];
p = polyfit(x,y,6);
x1 = 2:0.01:15;
y1 = polyval(p,x1);
figure
plot(x,y,'*',x1,y1,'r')
xlabel 'x 轴' 
ylabel 'y 轴' 
title('最小二乘polyfit拟合图') 
figure
bar(x,polyval(p,x)-y)
xlabel 'x 轴' 
ylabel '残差' 
title('最小二乘polyfit拟合图') 

k = length(x); 
X=[ones(k,1) x' x.^2' x.^3']; 
[b, bint, r, rint, stats] = regress(y',X);
x2 = 2:0.01:15;
y2 = b(1)+b(2)*x2+x2.^2*b(3)+x2.^3*b(4);
figure
plot(x,y,'*',x2,y2,'r')
xlabel 'x 轴' 
ylabel 'y 轴' 
title('最小二乘regress拟合图') 
figure
bar(x,r)
xlabel 'x 轴' 
ylabel '残差' 
title('最小二乘regress拟合图') 

 

4、参考论文

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