Thanks Evgeny Pr, for reply.
I don't want to use it for a complex case, for example;
consider two subplots that contain a function and its derivative
subplot(2,1,1) plot (f(x,t))
subplot(2,1,2) plot (df(x,t)/dt)
So, for this 2-D graphs, can we apply the dragzoom function at the same time for both subplots?