Try this:
x=0.1:0.1:1;
n=length(x);
f=exp(x);
y=f+0.1*randn(1,n);
plot(x, f, 'b-', 'LineWidth', 3);
grid on;
hold on;
plot(x, y, 'x', 'color',[.5 .5 .5], 'LineWidth', 2, 'MarkerSize', 9)
legend('function f','measurement y');
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
% Get rid of tool bar and pulldown menus that are along top of figure.
set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')