I am trying to have a quadratic fit to my data.
X = randi(100,[40, 1])
Y = (2* (X.^2)) +(3*X) +(5);
X2 = [ones(size(X)) X X.^2]
m3 = X2 \ Y;
y3 = X2*m3;
title('y= ax^2+bx+c', 'FontSize',18)
However, when I display the plot istead of a single parabolic fir I am getting multiple lines.
Please help. I experimented this while learning linear regression.