MATLAB: Fitting a linear sine curve with polynomial curve

approximationcurve fitting

I don't have any data points. I have seen your past answers of fitting the sinusoidal function using pure Matlab functions. But those coefficients is for non-linear sinusoidal function. Can you assist me in fitting a linear sine curve between o and 2pi with the polynomial curve of power 4? I am a noobie at Matlab coding. Kindly assist for the same.

Best Answer

x=linspace(0,2*pi,100);
x=transpose(x);
A=[ones(numel(x),1),x,x.^2,x.^3,x.^4];
b=sin(x);
sol=A\b; % Polynomial is given by sol(1)+sol(2)*x+sol(3)*x^2+sol(4)*x^3+sol(5)*x^4
Best wishes
Torsten.