How can I add the arrow to the graph like this picture ?

http://free.ssc.vn/images/98img_therm30_1.png

I make a plot in GUI, How can I add the arrow on the graph like the picture ? help me. Thanks you very much.

Answer 1

[Image Analyst]

Nguyen, there is an annotation function that will do arrows:

annotation('arrow',x,y)
annotation('doublearrow',x,y)
annotation('textarrow',x,y)

But the arrows are straight, not curving/swooping . To get curved arrows like you showed, you'd have to create the curving/swooping lines and then use plot() to plot them. Then you'd have to set "hold on" and call annotation to put a small arrow on top of the curving line you drew with plot().

[Nguyen Trong Nhan]

I want the arrow lying on graph to point the direction of thermodynamics cycle. How I have to use annotation to do that ? Could you give me an example.I'm freshman in Vietnam. Hope you help me. thanks

[Image Analyst]

plot(x,y, 'k-');
annotation('arrow', [.3 .5], [.6 .5]);

Answer 2

[Youssef Khmou]

Nguyen, That is thermodynamic cycle, there might be a solution, however try this temporary example :

X=[2 4 4 2 2];  Y=[2 1 5 7 2];
plot(X,Y)
axis([0 7 0 7])
xlabel('Volume'), ylabel('Pressure');

Try then to put carefully the arrows with these commands :

gtext('>','FontSize',20,'Rotation',-30);
gtext('<','FontSize',20,'Rotation',-30);
gtext('<','FontSize',20,'Rotation',-90);
gtext('<','FontSize',20,'Rotation',90);

Try to choose the right angle in the property "Rotation" .

[Nguyen Trong Nhan]

Anyway thanks a lot