fix(demos): plot the unit-values time series off a plain frame

[thodson-usgs]

What

One line in demos/hydroshare/USGS_WaterData_UnitValues_Examples.ipynb:

-ax = discharge[0].plot(x="time", y="value", style=".")
+ax = discharge[0][["time", "value"]].plot(x="time", y="value", style=".")

Why

The cell raised TypeError: Axes.scatter() got multiple values for argument 'x'. Because conf.py sets nbsphinx_allow_errors = True, this did not fail the docs build — it rendered the traceback on the published example page instead, which is why it went unnoticed.

waterdata.get_continuous returns a GeoDataFrame, and GeoDataFrame.plot() dispatches to the geospatial plot unless a pandas kind is given. So x="time" was carried through as a style keyword down into ax.scatter(x, y, **kwargs), which already had x positionally.

Subsetting to the two plotted columns yields a plain DataFrame and therefore the pandas plot. That is exactly what the two sibling notebooks doing the same time-series plot already do:

dailyStreamflow[0][["time", "value"]].plot(x="time", y="value")          # DailyValues
data[0][["time", "value"]].plot(x="time", y="value", style=".")          # GroundwaterLevels
discharge[0].plot(x="time", y="value", style=".")                        # UnitValues — the only one missing it

So this restores the established convention rather than introducing a new one. (kind="line" also fixes it, but would make this notebook the odd one out.)

Testing

All 23 tracked notebooks were executed against the live APIs. Result: 21 passed, 2 failed.

• This one — fixed here, and re-verified by executing the notebook end to end afterwards.
• demos/R Python Vignette equivalents.ipynb — not a code defect. It fails on waterqualitydata.us with SSL: CERTIFICATE_VERIFY_FAILED … self-signed certificate in certificate chain, an artifact of a TLS-intercepting proxy on the machine that ran it. api.waterdata.usgs.gov was reachable in the same run. Nothing to change.

🤖 Generated with Claude Code

https://claude.ai/code/session_01BTaSm7HmVb94RSJiKW4WAS