Preprocess camera ingress-egress timestamps

Converts paired ingress and egress POSIXct timestamps into a data frame of daily angler-effort hours, suitable for passing to add_counts. Duration for each pair is computed as difftime(egress_col, ingress_col, units = "hours"). Pairs where egress precedes ingress (negative duration) are flagged with cli_warn and excluded from the daily sum (set to NA).

Usage

preprocess_camera_timestamps(timestamps, date_col, ingress_col, egress_col)

Arguments

timestamps

A data frame containing the ingress-egress records.

date_col

Tidy selector for the date column (Date or POSIXct).

ingress_col

Tidy selector for the ingress timestamp column (POSIXct).

egress_col

Tidy selector for the egress timestamp column (POSIXct).

Value

A data frame with columns date and daily_effort_hours (one row per unique date, effort hours summed across all valid pairs for that date).

Details

Preprocess camera ingress-egress timestamps to daily effort hours

Examples

# Camera timestamps: one row per angler arrival/departure pair.
ts <- data.frame(
  survey_date  = rep(as.Date(c("2024-06-01", "2024-06-02")), each = 2L),
  ingress_time = as.POSIXct(
    c("2024-06-01 06:00:00", "2024-06-01 09:00:00",
      "2024-06-02 07:00:00", "2024-06-02 10:30:00"), tz = "UTC"
  ),
  egress_time = as.POSIXct(
    c("2024-06-01 08:00:00", "2024-06-01 11:00:00",
      "2024-06-02 09:00:00", "2024-06-02 13:00:00"), tz = "UTC"
  )
)
preprocess_camera_timestamps(ts, date_col = "survey_date",
                             ingress_col = "ingress_time",
                             egress_col = "egress_time")
#>         date daily_effort_hours
#> 1 2024-06-01                4.0
#> 2 2024-06-02                4.5