Timepoint clarification

[mobilitydataio]

Requirements

Datasets that have all departure/arrival_time populated and that use a mix of specified and empty timepoint values (sample 1 https://github.com/google/transit/pull/474#issue-2339968072).

empty timepoint values used to inform that times are exact (example) -> should be replaced with values 1 empty timepoint values used to inform that times are approximate (example) -> should be replaced with values 0 Datasets with omitted times and timepoint values 1 for records with times (sample 2 https://github.com/google/transit/pull/474#issue-2339968072, example): they won't trigger a WARNING anymore.

Flex datasets that don't use departure/arrival_time and don't have timepoint defined: they won't trigger a WARNING anymore.

If this PR gets merged, we will make a modification of the canonical validator, as its logic is currently to give a WARNINGS in all cases of timepoint="".

Commit Nº 1

AUTHOR × DATE

• isabelle-dr ( isabelle-dr )
• August 1, 2024 @ 05:23 AM ETC (09:23 AM UTC)

  MESSAGE

  
  Clarify intended use for timepoint in stop_times.txt (#474)

• Update reference.md
• Add statement that all values with times should have timepoint values
• small change
• Timepoint values should be set to 0 for records with no times
• Minor change
• Minor wording change
• Change to resolution 1

  
  ## FILES CHANGED
  > ### https://github.com/google/transit/commit/b2ee3c857e2ac0216e5ef4c8a6447901c4e16b71

https://github.com/google/transit/commit/b2ee3c857e2ac0216e5ef4c8a6447901c4e16b71

---

[isabelle-dr]

Here is the effect of this spec change on the validator.

Current validator behavior

• warning missing_recommended_column is triggered if stop_times.txt doesn't have the timepoint column header.
• warning missing_timepoint_value for records in stop_times.txt with timepoint == "" (i. e. no value provided) given that the timepoint header is provided in the file. This is regardless of the presence or not of times in departure_time and arrival_time.

New validator behavior

• a warning should be triggered for records in stop_times.txt that have values for at least one of the departure_time and arrival_time fields (i. e. they have times defined) AND timepoint == "" (i. e. no value provided).

With this new behavior, we don't need to distinguish between datasets that have the column header and those that don't. We could remove missing_recommended_column altogether because I don't believe it's used for anything else, and modify missing_timepoint_value. We could also use the more generic missing_recommended_field, if we are able to generate it with a condition.

Expected effect on production data The # datasets that trigger the new notice should be slightly smaller than the sum of the # datasets that trigger missing_recommended_column and missing_timepoint_value today (note that no dataset can trigger both, it's one or the other). This is because the datasets that have the following modeling will not trigger warnings anymore: stop_sequence	arrival_time	departure_time	timepoint
1	8:30:00	8:30:00	1
2	8:31:01	8:31:01	1
3
4
5
6
7
8
9
10	8:45:00	8:45:00	1
11	8:55:00	8:55:00	1

Additional note Note that the logic that triggers the error stop_time_timepoint_without_times is unchanged: it's triggered for datasets that have no times defined for records with timepoint == 1

cc @tzujenchanmbd

[emmambd]

Tasks:

• Remove missing_recommended_column notice (need to validate no other fields/files are affected)
• missing_timepoint_value functionality change to remove conditional on timepoint header presence AND add check if departure_time and arrival_time values exist