% TestLinfit.m   Feb. 2005 L Braile
% Test and plot the linfit least squares straight
% line function with sample data
x = [1 2 3 4 5 6 7 8 9];
y = [1.5 1.8 2.0 3.6 4.1 6.8 6.4 4.0 9.4];
mode = 0;
npts = length(x);
sigmay = ones(1,npts); % assume uncertainties in y are all = 1
% calculate and print least squares coefficients, sigmas and r
[a,sigmaa,b,sigmab,r] = linfit(x,y,sigmay,npts,mode)
% plot the data and least squares line
plot(x,y,'ro','markersize',12,'linewidth',3) % Plot the data
set(gca,'fontsize',16,'linewidth',2)
hold on
xlabel('x-values','fontsize',16)
ylabel('y-values','fontsize',16)
title('Plot of sample data and least squares straight line fit','fontsize',16)
yt = feval('sline',x,a,b); % Calculate the fitted line
plot(x,yt,'k-','linewidth',3) % Plot the fitted line
axis([0 10 0 10]); % Set axis limits for plot
hold off