qt3scope - unbound cache error matplotlib.animation

[gadamc]

When installing and running qt3scope on the QDL in B069, a warning was reported to the console at startup. The warning was issued for line 161 of oscilloscope.py and mentioned "did not pass explicit save_count"

However, qt3scope seemed to work as expected.

[NnguyenHTommy]

Similarly, when installing and running qt3scope on the SiV microscope in B065, a warning was reported:
C:\Users\SiV Microscope\anaconda3\envs\qt3-producers\lib\site-packages\applications\oscilloscope.py:161: UserWarning: frames=<bound method RateCounterBase.yield_count_rate of <qt3utils.datagenerators.daqsamplers.NiDaqDigitalInputRateCounter object at 0x000001C4EC494190>> which we can infer the length of, did not pass an explicit save_count and passed cache_frame_data=True. To avoid a possibly unbounded cache, frame data caching has been disabled. To suppress this warning either pass cache_frame_data=False or save_count=MAX_FRAMES.
self.animation = animation.FuncAnimation(self.view.scope_view.fig,

[vasilisniaouris]

I have observed the same error on our big-magnet set-up in B069. For clarification, the only time it is used internally in matplotlib/lib/matplotlib/animation.FuncAnimation is around line 1760, where each generated frame data sequence (generated via the yield count rate method in our case) is stored internally in FuncAnimation._save_seq.

The warning is removed by passing a cache_frame_data=False to the animation.FrameAnimation function call. I believe that disabling the caching functionality is beneficial to animation speed, since we do not require to store any of the data as of now.