How to get accurate DataAspectRatio when stretch-to-fit is enabled?

Matlab documentation states that when stretch-to-fill is enabled (as it is by default), then "the axes might not exactly match the data aspect ratio, plot box aspect ratio, and camera-view angle values stored in its DataAspectRatio, PlotBoxAspectRatio, and CameraViewAngle properties." Setting the 'mode' of any one of these three properties to 'manual' should turn off stretch-to-fill. My issue is that I want an accurate reading of the DataAspectRatio without setting any of these to manual. A workaround seems to be temporarily setting PlotBoxAspectRatioMode to 'manual,' which has the effect of changing the value of DataAspectRatio to match what is on screen [1].

figure;plot(0.1:0.1:pi,sin(0.1:0.1:pi))
pbaspect manual
val = daspect
pbaspect auto

Or a safer way to do it if you want a generally useful script (e.g. in case PlotBoxAspectRatioMode is already manual and you don't want to change that) would be:

pbaspectMode = get(gca,'PlotBoxAspectRatioMode');
pbaspect manual;
val = daspect;
set(gca,'PlotBoxAspectRatioMode',pbaspectMode);

My question is - is this safe? Or will there be side effects, either occurring intermittently, or that are hard to detect?

[1] This is in contrast to as setting DataAspectRatioMode to 'manual,' which changes what's on screen to match the current value of DataAspectRatio. This is not what I want.

Answer 1

[Evan]

From Mathworks support:

The technique of setting bpaspect to manual and then back may be "safe" (although I wouldn't be surprised if there are side effects), but a better way is to divide:

real_daspect = daspect./pbaspect;