Changing x and y limits when using plotyy

I am using the guide and have a problem when trying to change the limits of the axes with two lines.

I have these sets of data: x, y1, y2

I have plotted them using the plotyy command:

     [AX, h1, h2] = plotyy(x,y1,x,y2)

This occurs in one function.

A separate function controls changing the axes limits. In this example, I want to 'pan up' by adding a tenth of the variable 'ylimsd' to the y-limits.

     ylims = ylim;
     ylims1 = ylims(1,1);
     ylims2 = ylims(1,2);
     ylimsd = ylims2 - ylims1;

Problem --> if I use:

     ylim(gca, ylim + (ylimsd/10))

only the line containing (x,y1) is affected, and the other line appears to be frozen and unaffected.

Is there any way I can 'pan' so that both lines move together?

P.S. I realise if I were to set the y limits immediately after the plotyy (i.e. in the same function) I could use the following code:

    set(AX(1),'Ylim',ylim + (ylimsd/10)) 
    set(AX(2),'Ylim',ylim + (ylimsd/10))

BUT I am trying to 'pan' from a separate function, so 'AX' is undefined.

Answer 1

[Image Analyst]

The FAQ goes over how you can share the y axis handles or AX between different functions: http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F