MATLAB: How to generate second order best fit polynomial curve using MATLAB

Question

Hi all can anybody tell me how to generate above equation for this x and y data using MATLAB ? x,y coordinates are 100,200 200,500 300,900 400,1400 500,2000

Answer 1

Dan,

You can do this using poly2

x=[100 200 300 400 500]';
y=[200 500 900 1400 2000]';
ft = fittype( 'poly2' ); % Set up fittype and options.
[fitresult, gof] = fit( x, y, ft ); % Fit model to data.
f=@(x) fitresult.p1*x.^2+fitresult.p2*x+fitresult.p3;
plot(x,y,x,f(x),'o')