x_data = [ 0, 0.5, 1 ];
y_data = exp ( x_data );

x = linspace ( -0.5, 1.5, 25 );
y = exp ( x );
y2 = y_data(1) * ell(1,x_data,x)  ...
   + y_data(2) * ell(2,x_data,x)  ...
   + y_data(3) * ell(3,x_data,x);

plot ( x, y, 'b-', ...
       x, y2, 'r-', ...
       x_data, y_data, 'k.', 'markersize', 25 );

print ( '-dpng', 'exp_quadratic.png' );

