Questiona about pcolormesh behaviour with a non-linear time coordinate

[arthur-st]

I'm curious about this shading behaviour that I've spotted with xplt.pcolormesh.

plot_data[2] there is a DataArray with some 18 minute data gap that is not represented by linear coordinates. In other words, running this for the plot data above:

y = x.sel(time=slice(x.coords['time'][0] + pd.Timedelta(seconds=55, milliseconds=937), x.coords['time'][0] + pd.Timedelta(minutes=19, seconds=44)))
y.coords["time"]

Results in the following output:

<xarray.DataArray 'time' (time: 2)> Size: 16B
array(['2014-03-05T21:25:55.968000000', '2014-03-05T21:44:44.000000000'],
      dtype='datetime64[ns]')
Coordinates:
  * time     (time) datetime64[ns] 16B 2014-03-05T21:25:55.968000 2014-03-05T...

What I wonder about then is what is that colour break at around 21:35? I initially thought that it's some sort of gradient between the left and the right points, but checking on some other plot examples I have, that wouldn't be very consistent. For instance,

In this one the shading goes into a local minimum in the left/first "half" of the missing data area. But then again, I'm probably just dealing with some weird/undefined behaviour here.

My end goal here is fill that out with white/missing colour, but I assume I'll need to compute a linear time coordinate space for that and fill out with NA the missing data with a Dataset.reindex operation. Please let me know if there's a better way to do that.