Improve algorithm for detecting airport size

assets/client.js

@@ -2,7 +2,21 @@
 
 const aircraftIndex = {}
 const airlineICAOIndex = {}
+const airportSize = {}
 const airportMarkers = []
+const INITIAL_ZOOM_LEVEL = 9
+const AIRPORT_VISIBILITY_THRESHOLD = [
+ null,
+ 200,
+ 150,
+ 120,
+ 100,
+ 80,
+ 60,
+ 40,
+ 20,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+]
 const infoPanel = document.getElementById('info')
 let map, selectedMarker, planeIcon, currentPosition, openInfoWindow
 
@@ -33,7 +47,7 @@ function initMap () {
 
  // eslint-disable-next-line no-undef
  map = new google.maps.Map(document.getElementById('map'), {
- zoom: 9,
+ zoom: INITIAL_ZOOM_LEVEL,
  center: currentPosition
  ? new google.maps.LatLng(currentPosition.lat, currentPosition.lng) // eslint-disable-line no-undef
  : new google.maps.LatLng(48.9062802, 2.3598659) // eslint-disable-line no-undef
@@ -42,7 +56,9 @@ function initMap () {
  map.addListener('zoom_changed', zoomLevelChanged)
 
  onJQuery(function ($) {
- $.getJSON('airports', plotAirports).fail(onAjaxError)
+ $.getJSON('routes', parseRoutes).fail(onAjaxError).done(function () {
+ $.getJSON('airports', plotAirports).fail(onAjaxError)
+ })
  $.getJSON('airlines', parseAirlines).fail(onAjaxError)
  setInterval(function () {
  $.getJSON('aircrafts', plotAircrafts).fail(onAjaxError)
@@ -57,13 +73,9 @@ function onAjaxError (jqXHR, textStatus, err) {
 function zoomLevelChanged () {
  const level = map.getZoom()
  airportMarkers.forEach(function (marker) {
- let visible = true
- if (level >= 6 && level <= 7) {
- visible = !!marker.airport.IATA
- } else if (level < 6) {
- visible = false
- }
- marker.setVisible(visible)
+ const size = airportSize[marker.airport.IATA]
+ const threshold = AIRPORT_VISIBILITY_THRESHOLD[level]
+ marker.setVisible(threshold ? size > threshold : true)
  })
 }
 
@@ -73,6 +85,20 @@ function parseAirlines (airlines) {
  })
 }
 
+function parseRoutes (routes) {
+ routes.forEach(function (route) {
+ tickAirport(route.source)
+ tickAirport(route.dest)
+ })
+}
+
+// Keep a record of how many routes fly to and from a given airport.
+// This helps us know how big an airport is.
+function tickAirport (IATA) {
+ if (!airportSize[IATA]) airportSize[IATA] = 1
+ else airportSize[IATA]++
+}
+
 function plotAirports (airports) {
  const airportIcon = {
  path: 'M182.9,551.7c0,0.1,0.2,0.3,0.2,0.3S358.3,283,358.3,194.6c0-130.1-88.8-186.7-175.4-186.9 C96.3,7.9,7.5,64.5,7.5,194.6c0,88.4,175.3,357.4,175.3,357.4S182.9,551.7,182.9,551.7z M122.2,187.2c0-33.6,27.2-60.8,60.8-60.8 c33.6,0,60.8,27.2,60.8,60.8S216.5,248,182.9,248C149.4,248,122.2,220.8,122.2,187.2z',
@@ -81,14 +107,17 @@ function plotAirports (airports) {
  fillOpacity: 1,
  scale: 0.03
  }
+ const visibilityThreshold = AIRPORT_VISIBILITY_THRESHOLD[INITIAL_ZOOM_LEVEL]
 
  airports.forEach(function (airport) {
+ const size = airportSize[airport.IATA]
  // eslint-disable-next-line no-undef
  const marker = new google.maps.Marker({
  position: {lat: airport.lat, lng: airport.lng},
  map: map,
  title: airport.name,
- icon: airportIcon
+ icon: airportIcon,
+ visible: visibilityThreshold ? size > visibilityThreshold : true
  })
  marker.airport = airport
  // eslint-disable-next-line no-undef

lib/routes.js

@@ -84,6 +84,35 @@ exports.airports = function (req, res) {
  })
 }
 
+exports.routes = function (req, res) {
+ let first = true
+ res.setHeader('Content-Type', 'application/json')
+
+ fs.createReadStream(path.join(__dirname, '..', 'data', 'routes.csv'))
+ .pipe(csv(['airline', 'airlineId', 'source', 'sourceId', 'dest', 'destId', 'codeshare', 'stops', 'equipment']))
+ .on('error', function (err) {
+ console.error(err.stack)
+ if (first) res.writeHead(500)
+ res.end()
+ })
+ .on('data', function (row) {
+ Object.keys(row).forEach(function (key) {
+ if (row[key] === '\\N') row[key] = null
+ })
+ row.airlineId = Number.parseInt(row.airlineId, 10)
+ row.sourceId = Number.parseInt(row.sourceId, 10)
+ row.destId = Number.parseInt(row.destId, 10)
+ row.codeshare = row.codeshare === 'Y'
+ row.stops = Number.parseInt(row.stops, 10)
+
+ res.write((first ? '[\n' : ',') + JSON.stringify(row) + '\n')
+ first = false
+ })
+ .on('end', function () {
+ res.end(']')
+ })
+}
+
 exports.aircrafts = function (req, res) {
  const aircrafts = store
  .getAircrafts()

package.json

@@ -19,9 +19,10 @@
  "standard": "^10.0.3"
  },
  "scripts": {
- "data": "npm run data-airlines && npm run data-airports",
+ "data": "npm run data-airlines && npm run data-airports && npm run data-routes",
  "data-airlines": "mkdir -p data && curl -o data/airlines.csv https://raw.githubusercontent.com/jpatokal/openflights/master/data/airlines.dat",
  "data-airports": "mkdir -p data && curl -o data/airports.csv https://raw.githubusercontent.com/jpatokal/openflights/master/data/airports.dat",
+ "data-routes": "mkdir -p data && curl -o data/routes.csv https://raw.githubusercontent.com/jpatokal/openflights/master/data/routes.dat",
  "postinstall": "npm run data",
  "test": "standard"
  },

server.js

@@ -30,6 +30,7 @@ patterns.add('GET /', routes.index)
 patterns.add('GET /assets/{file}', routes.assets)
 patterns.add('GET /airlines', routes.airlines)
 patterns.add('GET /airports', routes.airports)
+patterns.add('GET /routes', routes.routes)
 patterns.add('GET /aircrafts', routes.aircrafts)
 
 const server = http.createServer(function (req, res) {