% set values for x and y, the raw data
x = [1;2;3;4;5];
y = [2.1;3.8;6.0;9.;11.1];

% set values for the error bars for each point
e = [0.7,0.3,0.5,0.2,0.3];

% fit a first order polynomial (i.e. straight line) to the data,
% "p" has the two coefficients for the straight line.
p=polyfit(x,y,1);

% generate a set of yy values for each x using the curve fit.
yy=polyval(p,x);

% plot the results ("hold on" puts the output of "errorbar" and "plot" 
% onto the same figure)

hold on;
errorbar(x,y,e,'o')
plot(x,yy,'r')
xlabel('x_o (m)')
ylabel('y_o (m)')