myfitn.m

自己编写的matlab程序 数值分析里的程序

%myfitn([2 3 4 5 6 7 8 9],5)
% n次多项式的最小二乘法
function y=myfitn(X,n)
syms x a b c;
m=length(X);
for i=1:m
    Y(i)=fun(X(i));    
end
for i=1:m
    for j=1:n+1
        T(i,j)=X(i)^(j-1);
    end
end
A=T'*T;
B=T'*Y';
C=A\B;
y=C(1);
for i=1:n
    y=y+C(i+1)*x^i;
end
y=vpa(y,6);
ezplot(y,[0 10])
hold on
fplot('fun(s)',[0 10],'r')
hold on
plot(X,Y,'ks')
hold off