* add keyword 'label' to degradation_timeseries_plot, enabling 'left' and 'center' labeling options.

* Update changelog, add pytests, update sphinx documentation

* fix flake8 grumbles

* update pytests to include axes limits

* fix flake8 grumbles

* add 'label' input option to `degradation_year_on_year`. Fixes #459

* add pytests and update changelog.

* flake8 grumbles

* Minor updates to setup.py (constrain scipy<1.16) and refactor degradation_test

* Custom fix for Pandas < 2.0.0 which can't average two columns of timestamps.

* flake8 grumbles

* keep TZ-aware timestamps.  Update pytests to specifically test _avg_timestamp_old_Pandas

* flake8 grumbles

* try to UTC localize the pytest...

* Add .asfreq() to get pytests to agree

* switch to calendar.timegm to hopefully remove TZ issues..

* regardless of uncertainty_method, return calc_info{'YoY_values')

* update _right dt labels to correct _left labels in degradation_year_on_year

* update _avg_timestamp_old_Pandas to allow for numeric index instead of timestamp

* add left label option to degradation_year_on_year

* update degradation_year_on_year, index set to either left, center or right. Consistent with #394 - multi_yoy

* update return for default = none uncertainty option

* degradation_year_on_year - go back to single return when uncertainty_value = None to avoid breaking pytests.

* add multi-year aggregation of slopes in degradation_year_on_year

* add multi_yoy kwarg in degradation_year_on_year to toggle the multi-YoY function.

* update plotting for detailed=True, allow usage_of_points > 2

* flake8 grumbles

* update plotting detailed=True for  (even) and (odd) number of points coloring

* To allow multi_yoy=True in plotting.degradation_timeseries_plot, resample.mean() the YoY_values.

* flake8 grumbles

* Add warning to degradation_timeseries_plot when multi_YoY=True

* update to warning message in plotting.degradation_timeseries_plot

* fix flake8 grumbles

* nbval fixes from qnguyen345-bare_except_error

* Add pandas 3.0 futurewarning handling

* Try again to solve pandas3.0 futurewarning

* attempt 3 to fix nbval

* Add infer_objects to remove futurewarning

* minor inline comment update

* update plotting tests to be relative value, update ordering of module import in plotting.py, per Copilot review.

* update inline comments and whatsnew docs

* Clean up inline comments per Copilot review

* added multi-YoY pytest - still need to catch warnings

* Add a warnings.catch_warnings to the plotting pytest

* flake8 grumbles

* add multi-YoY=True pytest

* updated changelog

* update changelog

* implement copilot suggestions

* linting

* use s instead of ns for pandas 3 compatibility

* update pandas version comparison

* set matplotlib non-gui backend for tests

* set dtype resolution based on pandas version

* linting import order

* boost degradation.py test coverage

* update changelog

* exclude coverage reports with suffixes

* Update rdtools/degradation.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* remove label=None handling, rely on default 'right' behavior

* refactor dt_center  tz handling for old pandas

* simplify _avg_timestamp_old_Pandas

* degradation_timeseries_plot: change rolling median min_periods to rolling_days / 4.

* remove degradation_timeseries_plot(label=) and just default to center=True

* update sensor_analysis() and clearsky_analysis() docstrings to discuss passing `label=right` kwargs

* flake8 updates

* Initial commit - multi-YoY notebook

* pretty-print notebook dataframes with tabulate.

* update notebook requirements to silence pandas warnings

* add multi-yoy nb to tutorials

* fix nblink path

* Change the yoy_values index to be named 'dt'.  Add new illustrations at the end of the multi-YoY notebook.

---------

Co-authored-by: Michael Deceglie <mdeceglie@users.noreply.github.com>
Co-authored-by: martin-springer <martinspringer.ms@gmail.com>
Co-authored-by: Martin Springer <97482055+martin-springer@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>