Comments on: Determining axes zoom state

By: tim

tim — Mon, 04 Jul 2016 04:10:33 +0000

The suggested solution seems to fail when zoom is constrained to only one axis and/or zoom mode is changed. Not all lim fields exist in ‘matlab_graphics_resetplotview’ for constrained axis zoom (so testing the others will throw an error). It also seems that fields are not updated when zoom mode is changed (eg from horizontal to unconstrained). A change in mode can however be detected by comparing gca’s limmode for each axis to those in matlab_graphics_resetplotview. But I don’t think it is then possible to tell if the current zoom value (ie lim) is different to its original setting if that axis did not have its zoom mode on originally.
A minimalist solution would be to store the 3 axes’ limits on creation.

NB r2016a

By: Adee Ran

Adee Ran — Sun, 29 May 2016 15:32:31 +0000

Thanks for exposing this (yet another) undocumented feature! I used a variant to set the "original zoom" of only the horizontal axis - which "zoom reset" does not seem to support:

rpv = getappdata(gca, 'matlab_graphics_resetplotview');
rpv.XLim = [tmin tmax]; % Use values calculated elsewhere
setappdata(gca, 'matlab_graphics_resetplotview', rpv);

Works like a charm.

By: Eduard Braun

Eduard Braun — Sun, 13 Sep 2015 14:03:58 +0000

In reply to Eduard Braun. Thanks for feedback! I had looked at zoom before but sadly it doesn't allow set specific numeric limits on the axes which makes it useless for many cases. However it turned out the actual solution is pretty simple: 1. Set the limits of the axes to the desired "zoomed out" state by setting appropriate limits. 2. Use zoom(figure,'reset') - this is were the "magic" happens and the current state of the figure is internally saved as the completely zoomed out state. 3. Achieve the desired zooming by simply setting appropriate limits on the axes. Steps 1 and 3 look redundant (and one would actually end up with the same visible content when just executing step 3.), however if one omits steps 1. and 2. it would not be possible to manually zoom out of the figure again!

By: Yair Altman

Yair Altman — Sun, 13 Sep 2015 07:17:14 +0000

In reply to Eduard Braun. @Eduard - you can use the zoom function with a certain factor, for example, zoom(2.5)

By: Eduard Braun

Eduard Braun — Sat, 12 Sep 2015 22:30:34 +0000

This is a very interesting way to determine if the axes are zoomed. However I'm wondering if it is possible to do this the other way round: Start with unzoomed axes and programmatically bring them into a state as if they were zoomed in by the user? For clarification: If I simply set XLim and/or YLim on the axes I can zoom in a portion of the graph but the user can not zoom out anymore... Therefore it's not the same as if the user zoomed in (since then he obviously can zoom out again).

By: Yair Altman

Yair Altman — Fri, 10 Oct 2014 10:16:35 +0000

In reply to Adam. @Adam - there are numerous small changes in 14b that are not officially documented. I guess this is yet another example.

By: Adam

Adam — Fri, 10 Oct 2014 10:14:20 +0000

Hi Yair. Do you know if something has changed in R2014b that would cause this to no longer work when the figure containing the axes is not yet visible when zoom reset is called? It is one of a number of related things in my code that has broken from R2014a all seemingly related to whether or not a figure is actually visible yet or whether it is the figure in focus. I fixed this case by just checking if the zoominfo object is empty (it is now in R2014b, it wasn’t in R2014a when triggered from the OpeningFcn) and another case where creating a zoom object without an explicit figure used to match to the correct figure by default in R2013a, but picked up the figure that spawned it instead in R2014b was easy to fix.

I couldn’t see anything in the described graphics changes though that would explain this behaviour. My troubles with findjobj also seem to relate to this type of issue, seemingly EDT effects that were not present in R2014a, but now break the code in R2014b. In that case I just had to stop using the functionality, at least until I have more time to investigate. The axis zoom state information in this blog has been very useful to me though so thank you for sharing.

By: Yair Altman

Yair Altman — Fri, 09 May 2014 13:47:14 +0000

In reply to Aleksander Hammernes.

xlimits = get(hAxes,'xlim');
ylimits = get(hAxes,'ylim');

By: Aleksander Hammernes

Aleksander Hammernes — Fri, 09 May 2014 11:46:27 +0000

Would it be possible to get the zoom area ?
let say you activate the zoom function in a axes, normally this off course works fine, you can click and drag your mouse inside
the axes, and it zoom`s the axes to your wishes. how ever not in my gui…… in need to replot to make it work for me, so is there a
way to “capture” the x and y limits from the drag dragable zoom ?

By: Yair Altman

Yair Altman — Sat, 12 Nov 2011 15:34:02 +0000

In reply to Richard.

@Richard – take a look at the undocumented hidden axes property LooseInset: http://undocumentedmatlab.com/blog/axes-looseinset-property/