demonstrate line_fit

clear
close all
load pset1

[pm, k, qrng, epts] = line_fit(x, y);
disp(qrng);

   -9.0397    9.1805

plot(epts(:,1),epts(:,2),'k','LineWidth',2);
hold on
plot(x,y,'ko','MarkerFaceColor','y');
hold off
grid
xlabel('x');
ylabel('y');

figure
dpts = [x-pm(1); y-pm(2)];
u = k*dpts;
v = [-k(2) k(1)]*dpts;
plot(u,v,'ko','MarkerFaceColor','y');
rng = [min(u) max(u)];
hold on
plot(rng,[0 0],'k','LineWidth',2);

hold off
grid
xlabel('u');
ylabel('v');