Generate individual retrospective accessibility feeds

[mrtopsyt]

Changes

• Added a notebook to generate retrospective accessibility feeds given a schedule feed and a gtfs schedule dataset name, by filtering trips.txt to remove trips that are not in the schedule, and by re-creating stop_times.txt to have values based on the schedule_rt_stop_times gtfs funnel tables.
• Included functions to impute values in defined cases to ensure that feeds can be accepted by trip planners:
  • All first/last trips, regardless of whether a rt time is entered
  • Stops where the real time arrival time does not monotonically increase
  • Stops where rt times are unavailable for fewer than a configured number of stops
• Added flexibility in case rt / schedule feed format changes
• Included basic documentation

Known Issues

• Unsure of how to generate the "left merged" schedule rt stop times - currently an "inner merged" version is generated in the gtfs funnel, but the functions to generate it are not in a package. For now I just copied the functions to a separate file, but ideally these tables would be generated as part of the gtfs funnel, and I'm not entirely sure how to best handle that.
• Need to better test imputation functions

[github-actions]

nbviewer URLs for impacted notebooks:

• realizable_transit_accessibility/retrospective_feed_generation.ipynb
• realizable_transit_accessibility/rt_schedule_anomaly_exploration.ipynb
• realizable_transit_accessibility/rt_stop_times_exploration.ipynb
• rt_scheduled_v_ran/scripts/rt_stop_times_exploration.ipynb

[github-actions]

nbviewer URLs for impacted notebooks:

• realizable_transit_accessibility/retrospective_feed_generation.ipynb
• realizable_transit_accessibility/rt_schedule_anomaly_exploration.ipynb
• realizable_transit_accessibility/rt_stop_times_exploration.ipynb
• rt_scheduled_v_ran/scripts/rt_stop_times_exploration.ipynb

[edasmalchi]

looks good! I added a couple lines to one notebook (note to install gtfs-lite, create output dir if necessary).

[edasmalchi]

looks great!