R/check_gps_coordinates.R

In Thaliehln/timci: Data management and visualisation for the TIMCI project

#' Find Closest Facility
#'
#' This function finds the closest facility from a data frame to a set of facilities
#'
#' @param df A data frame containing longitude and latitude information for each point
#' @param facilities A data frame containing longitude and latitude information for each facility
#'
#' @return A data frame with the closest facilities within a distance of 100 units
#'
#' @import dplyr
#' @import geosphere
#'
#' @export

find_closest_facility <- function(df,
                                  facilities) {

  out <- df

  cols <- colnames(df)
  facilities <- facilities %>%
    dplyr::distinct(facility_id, .keep_all = TRUE)

  if ( "longitude" %in% cols ) {

    # Filter out and save for later records that do not have GPS coordinates
    wo_gps_df <- df %>%
      dplyr::filter(longitude == "" | is.na(longitude))

    tmp2 <- df %>%
      dplyr::filter(longitude != "" & !is.na(longitude))

    facilities2 <- facilities %>%
      dplyr::rename(lon = Longitude,
                    lat = Latitude) %>%
      dplyr::slice(rep(row_number(), nrow(tmp2)))

    tmp2 <- tmp2 %>%
      dplyr::slice(rep(row_number(), nrow(facilities)))

    if ( nrow(tmp2) > 0 ) {

      out <- tmp2[order(tmp2$uuid,
                        na.last = TRUE,
                        decreasing = FALSE),] %>%
        dplyr::bind_cols(facilities2) %>%
        dplyr::rowwise() %>%
        dplyr::mutate(dist = geosphere::distHaversine(c(as.numeric(longitude), as.numeric(latitude)),
                                                      c(as.numeric(lon), as.numeric(lat)))) %>%
        dplyr::ungroup() %>%
        dplyr::filter(dist < 200) %>%
        dplyr::filter(fid != facility_id) %>%
        dplyr::bind_rows(wo_gps_df)

      out <- out[order(out$dist,
                       na.last = TRUE,
                       decreasing = FALSE),] %>%
        dplyr::distinct(uuid, .keep_all = TRUE)

    }

  }

  out

}