Removes observations occurring before a trip's minimum distance, or after a trip's maximum distance.

Sometimes observations will be recorded under a trip ID while a vehicle is still traveling in the opposite direction. Conversely, a trip may continue recording as it begins traversing the opposite direction. This function attempts to remove these observations by identifying each trip's minimum (beginning) and maximum (ending) distance, then filtering to only observations after and before these points. For both ends, the first occurrence of the beginning/maximum value is used.

Usage

trim_trips(distance_df, trim_type = "both", return_removals = FALSE)

Arguments

distance_df: A dataframe of linearized AVL data. Must include trip_id_performed, event_timestamp, and distance.
trim_type: Optional. A string, indicating whether the beginning of trips, end of trips, or both beginning and end of trips should be trimmed. Must be one of "beginning", "end", or "both". Default is "beginning".
return_removals: Optional. A boolean, should the function return a dataframe of points removed and why? Default is FALSE.

Value

The input distance_df with violating points removed. If return_removals = TRUE, a dataframe with observations removed and why.

Examples

# Get input data
c53_clean_trips <- new_transittraj_data("clean_incomplete_trips")
dim(c53_clean_trips)
#> [1] 627  11

# Run function
c53_trimmed <- trim_trips(distance_df = c53_clean_trips)
dim(c53_trimmed)
#> [1] 625  11
head(c53_trimmed)
#> # A tibble: 6 × 11
#>   location_ping_id vehicle_id trip_id_performed service_date route_id
#>   <chr>            <chr>      <chr>             <date>       <chr>   
#> 1 12620            2836       1306100           2026-02-16   C53     
#> 2 12647            2836       1306100           2026-02-16   C53     
#> 3 12728            2836       1306100           2026-02-16   C53     
#> 4 12809            2836       1306100           2026-02-16   C53     
#> 5 12890            2836       1306100           2026-02-16   C53     
#> 6 12971            2836       1306100           2026-02-16   C53     
#> # ℹ 6 more variables: direction_id <dbl>, speed <dbl>,
#> #   trip_stop_sequence <dbl>, event_timestamp <dttm>, stop_id <int>,
#> #   distance <dbl>