flights.R

# rm(list = ls())

# output: github_document always_allow_html: yes

library(pacman)
# rm(list = ls())


library(pacman)
p_load(
  dplyr,
  jsonlite,
  readxl,
  geosphere,
  leaflet,
  leaflet.extras,
  sf,
  tidygeocoder
)


# Find airports----
myflights <- read_excel("./assets/data/flights.xlsx")
tosearch <- data.frame(
  toloc =
    (sort(append(
      myflights$start,
      myflights$end
    ))),
  stringsAsFactors = F
)

tosearch <- tosearch %>%
  count(toloc) %>%
  arrange(desc(n)) %>%
  as.data.frame()

tosearch$tofun <- gsub(" ", "+", tosearch$toloc)
tosearch$tofun <- ifelse(tosearch$toloc == "San Sebastian",
                         "san+sebastian+es",
                         tosearch$tofun
)
tosearch$tofun <- ifelse(tosearch$toloc == "Lyon",
                         "Lyon+fr",
                         tosearch$tofun
)

airports <- function(place, n = 1, lang = "en") {
  url <- paste(
    "http://api.geonames.org/searchJSON?formatted=true&username=",
    GEONAMES_USER,
    "&style=medium&fcode=AIRP&lang=",
    lang,
    "&maxRows=",
    paste(n),
    "&q=",
    place,
    sep = ""
  )
  geonames <- fromJSON(url)
  geonames <- data.frame(geonames[["geonames"]])
  geonames$search <- place
  geonames <- geonames %>% select(
    tofun = search,
    toponymName,
    countryCode,
    long = lng,
    lat
  )
  return(geonames)
}

# Return
for (i in 1:nrow(tosearch)) {
  res <- airports(tosearch[i, c("tofun")])
  row.names(res) <- i
  if (i == 1) {
    final <- res
  } else {
    final <- rbind(final, res)
  }
  rm(res)
}
rm(i)
final$long <- as.numeric(final$long)
final$lat <- as.numeric(final$lat)

# Some statistics----
# Number times per city----
ndots <- left_join(tosearch, final) %>%
  select(
    name = toloc,
    countryCode,
    Airport = toponymName,
    n,
    long,
    lat
  )

# Connecting Routes----
connect <- myflights %>%
  count(start, end) %>%
  arrange(desc(n))
connect <- left_join(
  connect,
  ndots %>%
    select(
      start = name,
      long_init = long,
      lat_init = lat
    )
)
connect <- left_join(
  connect,
  ndots %>%
    select(
      end = name,
      long_end = long,
      lat_end = lat
    )
)


connectflights <- gcIntermediate(
  connect[, c("long_init", "lat_init")],
  connect[, c("long_end", "lat_end")],
  n = 100,
  breakAtDateLine = T,
  sp = T
)

linessf <- st_as_sf(connectflights)
data <- st_sf(connect, st_geometry(linessf))
kms <- sum((as.numeric(st_length(data)) * data$n) / 1000)
outline <- ndots[chull(ndots$long, ndots$lat), ]
# Leaflet-----
map <- leaflet(options = leafletOptions(minZoom = 1.5)) %>%
  addProviderTiles(providers$CartoDB.DarkMatter,
                   options = list(detectRetina = TRUE)
  ) %>%
  setView(-3.56948, 40.49181, zoom = 3) %>%
  setMaxBounds(-180, -90, 180, 90) %>%
  addCircleMarkers(
    data = ndots,
    radius = ndots$n^(1 / 5) * 5,
    stroke = T,
    fillOpacity = 0.3,
    group = "Destinations"
  )
map <- addPolygons(
  map = map,
  data = outline,
  lng = ~long,
  lat = ~lat,
  fillColor = "white",
  fillOpacity = 0.05,
  stroke = F,
  group = "Outline"
)
map <-
  addPolylines(
    map,
    weight = log(connect$n) * 6 + 3,
    opacity = 0.3,
    data = connectflights,
    col = "green",
    group = "Flights"
  )
map <- addEasyButton(
  map,
  easyButton(
    icon = "fa-globe",
    title = "Zoom to Level 1",
    onClick = JS(
      "function(btn, map){ map.setView([ 40.49181,-3.56948],1.25); }"
    )
  )
)
map <- addHeatmap(
  map,
  data = ndots,
  intensity = ndots$n^(1 / 5),
  max = max(ndots$n^(1 / 5)),
  minOpacity = 0.3,
  radius = 35,
  blur = 30,
  group = "Heatmap"
)

map <- addLayersControl(
  map,
  overlayGroups = c("Heatmap", "Destinations", "Flights", "Outline"),
  options = layersControlOptions(collapsed = TRUE)
)

map <- hideGroup(map, c("Destinations", "Flights", "Outline"))
map

htmlwidgets::saveWidget(map, "_scripts/where.html")