R/produce_departures_slice.R

In stupidpupil/wales_ish_r5r_runner: WalesIshR5R

produce_departures_slice <- function(start_time, fifteen_minute_intervals=(2*4)-1){
  con <- dbConnect(duckdb::duckdb())
  r5r_core <- setup_r5("data")

  lsoa_trip_points <- st_read("data/lsoa11_nearest_road_points.geojson") %>%
    mutate(id = LSOA11CD)

  departure_time_offsets <- (0:(fifteen_minute_intervals-1))*15

  ret <- tibble()

  for (offset in departure_time_offsets) {

    departure_time <- start_time + lubridate::dminutes(offset)
    print(departure_time)

    ttm <- travel_time_matrix(r5r_core = r5r_core,
      origins = lsoa_trip_points,
      destinations = lsoa_trip_points,
      mode = c('WALK', 'TRANSIT'),
      departure_datetime = departure_time,
      max_walk_time = 3000/60,
      max_trip_duration = (6*60),
      verbose = FALSE
      ) 

    ttm <- ttm %>%
      rename(
        travel_time_minutes = travel_time_p50
      ) %>%
      complete(from_id = lsoa_trip_points$id, to_id = lsoa_trip_points$id) %>%
      filter( from_id != to_id) %>%
      replace_na(list(travel_time_minutes = 99*60)) %>%
      mutate(
        departure_time = departure_time,
        arrival_time = departure_time + lubridate::dminutes(travel_time_minutes)
      )

    if( dbExistsTable(con, "departures_temp") ){
      dbAppendTable(con, "departures_temp", ttm)
    }else{
      dbWriteTable(con, "departures_temp", ttm)
    }

    ttm <- NULL
  }

  #ret <- ret %>%
  #group_by(from_id, to_id, arrival_time) %>% arrange(departure_time) %>% slice_tail() %>% ungroup()

  filename = paste0(
    "departures_slice_", 
    start_time %>% strftime("%Y-%m-%dT%H-%M"),
    "_", fifteen_minute_intervals, "x15.parquet")

  dbSendQuery(con, paste0("COPY (SELECT * FROM departures_temp) TO 'output/",filename,"' (FORMAT 'parquet');"))
  dbSendQuery(con, "DROP TABLE departures_temp;")

}