Getting handle for subplot of saved figure

Dear all,

I've a saved Matlab figure, which has several subplots. I would like to know how to get handles for different subplots after opening this figure.

Answer 1

[dpb]

A) If you know the number of subplots/orientation a priori, then

h=subplot(n,m,i);

will return the handle for the existing subplot at that location when gcf is the correct figure.

B) To find them not knowing the above, after hgload()

h=get(gcf,'children');

as the axes are the children of the figure; other stuff is descended from the axes object. Can always check on the above to ensure that

get(get(gcf,'children'),'type')

returns axes

[Lucky Tran]

A) Does not work because h=subplot() overwrites the existing subplot and returns handles to the newly created subplot.

B) Works but the explanation is incomplete. The axes handles need to be accessed using h(1), h(2), etc.

[dpb]

A) is NOT h=subplot(); but h=subplot(n,m,i); which WILL return the handle of the existing ith subplot without erasing it, and

B) is complete as to what the question raised; namely how to get the handles of the existing subplots.

[Walter Roberson]

h = subplot(n, m, i) will delete any existing axes that is overlayed by the implied position of the subplot, except that if there is an existing axes with that exact position then it will return the handle of that one axes instead of destroying it along with the other ones it overlaps.

[Walter Roberson]

When you h=get(gcf,'children') or h = findobj(gcf, 'type', 'axes') then the order of the various subplots in the children will match whatever order was in the figure when it was saved, which in turn depends upon the order in which the user created those axes. There is unfortunately no information saved with a subplot axes to indicate what combination of n, m, i were used to create it, so you need to deduce the relative subplot locations by examining the Position information.

[dpb]

NB: the given caveat on A) above...

"If you know the number of subplots/orientation a priori..."_ which is precisely the case in which the function returns the handle of the existing supblot at that place/orientation.

As for the latter; sure, if one doesn't save handles a priori and must go "handle-diving" to retrieve them later, more effort may (will be) required to use them than if had saved them in the first place.

[Walter Roberson]

If you had tweaked the position of the subplots at all then subplot() is probably going to destroy rather than find what you want :(

... Probably the easiest way to handle all this is to assign distinct tags to each subplot when it is created, and then to later retrieve by tag.

[dpb]

True, but that ship had sailed...at worst in OP's case if the figure had been munged on after creation all that's lost is a step of reading it again and using the other alternative of retrieving all handles. A nuisance, perhaps, but since he's starting with a saved figure already, nothing is going to be lost.