How to add a subfigure on top of an other figure?

I would like to add a subfigure on top of another figure, like a legend. For example like this: http://www.mdpi.com/sensors/sensors-12-03578/article_deploy/html/images/sensors-12-03578f3-1024.png

Answer 1

[Sean de Wolski]

Add another axes with the axes() command.

See the example here: doc axes

[Joseph Cheng]

so you'll then modify the new axes with the position parameter like:

figure(1)
mainAX = plot(magic(3).*randi(10,3,3));
subAX = axes('position',[.4 .7 .2 .2]);
xlabel('Voltage')
ylabel('current')