【前編】Google Geocoding APIを使用して平面地図にマッピング
2015.05.13
Category
Tags
とある案件で、世界各国のあるデータを平面の世界地図上にマッピングすることになったのですが、各国の座標のデータを作るのが手間なので、何とかならないかなと思っていたところ、Google Geocoding APIにたどり着きました。
Google Geocoding APIでは、住所の文字列から緯度経度を取得することができるので、国名のリストがあれば簡単に座標データを作れるなと思った次第です。
ただし、注意書きとして「ユーザーの入力にリアルタイムで応答することを目的としては設計されていません。」という一文がありました。どういうことだろうと思っていたのですが、使ってみて納得。結構厳しめの制限がありました。こちらに記述されてはいないのですが、1秒間で10回までしかAPIをコールできません。
つまり、200カ国以上ある国の座標のデータをリアルタイムで一瞬で作ることができません。よって、座標のデータは予めjsonデータ等にキャッシュしておく必要があります。このjsonデータを出力できる仕組みを作りました。
案件では国のデータでしたが、今回は各国の首都の座標データを作ることにしました。
まずは事前準備として、各国の国名と首都の名前をリスト化する必要があります。こちらよりコピペ、変形してJSで使える形に変換しました。このデータはJS内にハードコーディングしてしまっています。
次に準備するのは、変換する平面地図の画像です。地図の形式は色いろあるのですが、最も一般的と言われるミラー図法の地図を使っています。
使用した画像は以下のものです。
画像の幅、高さや、その他必要な値もスクリプト内にハードコーディングしています。特に意味はないです。
座標データ作成用のページは以下のリンクから。
途中経過が何となく分かるようにインジケータ的なものを何となくつけています。
※処理が完了すると、「complete」とalertされて、画面上にjsonのテキストが出力されるのですが、APIの制限があるため、「complete」と出ても何も表示されないことがあります。
※consoleを開くとリアルタイムで取得しているデータを見ることができます。
座標データ作成用のクラスです。
ハードコーディングしているデータが長いです。すみません。。jQueryも使用しています。
※Coffee Scriptを使用しています。
class project.MapData
@COUNTRY_DATA = [
{ country: "United Arab Emirates", capital: "Abu Dhabi" }
{ country: "Nigeria", capital: "Abuja" }
{ country: "Ghana", capital: "Accra" }
{ country: "Pitcairn Islands", capital: "Adamstown" }
{ country: "Ethiopia", capital: "Addis Ababa" }
{ country: "Algeria", capital: "Algiers" }
{ country: "Niue", capital: "Alofi" }
{ country: "Jordan", capital: "Amman" }
{ country: "Netherlands", capital: "Amsterdam" }
{ country: "Andorra", capital: "Andorra la Vella" }
{ country: "Turkey", capital: "Ankara" }
{ country: "Madagascar", capital: "Antananarivo" }
{ country: "Samoa", capital: "Apia" }
{ country: "Turkmenistan", capital: "Ashgabat" }
{ country: "Eritrea", capital: "Asmara" }
{ country: "Kazakhstan", capital: "Astana" }
{ country: "Paraguay", capital: "Asunción", query: "Asuncion" }
{ country: "Greece", capital: "Athens" }
{ country: "Cook Islands", capital: "Avarua" }
{ country: "Iraq", capital: "Baghdad" }
{ country: "Azerbaijan", capital: "Baku" }
{ country: "Mali", capital: "Bamako" }
{ country: "Brunei", capital: "Bandar Seri Begawan" }
{ country: "Thailand", capital: "Bangkok" }
{ country: "Central African Republic", capital: "Bangui" }
{ country: "Gambia", capital: "Banjul" }
{ country: "Saint Kitts and Nevis", capital: "Basseterre" }
{ country: "China", capital: "Beijing" }
{ country: "Lebanon", capital: "Beirut" }
{ country: "Serbia", capital: "Belgrade" }
{ country: "Belize", capital: "Belmopan" }
{ country: "Germany", capital: "Berlin" }
{ country: " Switzerland", capital: "Bern" }
{ country: "Kyrgyzstan", capital: "Bishkek" }
{ country: "Guinea-Bissau", capital: "Bissau" }
{ country: "Colombia", capital: "Bogotá" }
{ country: "Brazil", capital: "Brasília" }
{ country: "Slovakia", capital: "Bratislava" }
{ country: "Republic of the Congo", capital: "Brazzaville" }
{ country: "Barbados", capital: "Bridgetown" }
{ country: "Belgium", capital: "Brussels" }
{ country: "Romania", capital: "Bucharest" }
{ country: "Hungary", capital: "Budapest" }
{ country: "Argentina", capital: "Buenos Aires" }
{ country: "Burundi", capital: "Bujumbura" }
{ country: "Egypt", capital: "Cairo" }
{ country: "Australia", capital: "Canberra" }
{ country: "Venezuela", capital: "Caracas" }
{ country: "Saint Lucia", capital: "Castries" }
{ country: "French Guiana", capital: "Cayenne" }
{ country: "United States Virgin Islands", capital: "Charlotte Amalie" }
{ country: "Moldova", capital: "Chisinau" }
{ country: "Turks and Caicos Islands", capital: "Cockburn Town" }
{ country: "Guinea", capital: "Conakry" }
{ country: "Denmark", capital: "Copenhagen" }
{ country: "Senegal", capital: "Dakar" }
{ country: "Syria", capital: "Damascus" }
{ country: "Bangladesh", capital: "Dhaka" }
{ country: "East Timor (Timor-Leste)", capital: "Dili" }
{ country: "Djibouti", capital: "Djibouti" }
{ country: "Tanzania", capital: "Dodoma (official, legislative)" }
{ country: "Qatar", capital: "Doha" }
{ country: "Isle of Man", capital: "Douglas" }
{ country: "Ireland", capital: "Dublin" }
{ country: "Tajikistan", capital: "Dushanbe" }
{ country: "Tristan da Cunha", capital: "Edinburgh of the Seven Seas" }
{ country: "Sahrawi Arab Democratic Republic [c]", capital: "El Aaiún (declared)" }
{ country: "Akrotiri and Dhekelia", capital: "Episkopi Cantonment" }
{ country: "Christmas Island", capital: "Flying Fish Cove" }
{ country: "Sierra Leone", capital: "Freetown" }
{ country: "Tuvalu", capital: "Funafuti" }
{ country: "Botswana", capital: "Gaborone" }
{ country: "Cayman Islands", capital: "George Town" }
{ country: "Ascension Island", capital: "Georgetown" }
{ country: "Guyana", capital: "Georgetown" }
{ country: "Gibraltar", capital: "Gibraltar" }
{ country: "Guatemala", capital: "Guatemala City" }
{ country: "Saint Barthélemy", capital: "Gustavia" }
{ country: "Guam", capital: "Hagåtña" }
{ country: "Bermuda", capital: "Hamilton" }
{ country: "Easter Island", capital: "Hanga Roa" }
{ country: "Vietnam", capital: "Hanoi" }
{ country: "Zimbabwe", capital: "Harare" }
{ country: "Somaliland", capital: "Hargeisa" }
{ country: "Cuba", capital: "Havana" }
{ country: "Finland", capital: "Helsinki" }
{ country: "Hong Kong", capital: "Hong Kong" }
{ country: "Solomon Islands", capital: "Honiara" }
{ country: "Pakistan", capital: "Islamabad" }
{ country: "Indonesia", capital: "Jakarta" }
{ country: "Saint Helena", capital: "Jamestown" }
{ country: "Israel", capital: "Jerusalem (declared, de facto)" }
{ country: "State of Palestine", capital: "East Jerusalem (declared)" }
{ country: "State of Palestine", capital: "Ramallah (de facto)", query: "Ramallah" }
{ country: "South Sudan", capital: "Juba" }
{ country: "Afghanistan", capital: "Kabul" }
{ country: "Uganda", capital: "Kampala" }
{ country: "Nepal", capital: "Kathmandu" }
{ country: "Sudan", capital: "Khartoum" }
{ country: "Ukraine", capital: "Kiev" }
{ country: "Rwanda", capital: "Kigali" }
{ country: "South Georgia and the South Sandwich Islands", capital: "King Edward Point" }
{ country: "Jamaica", capital: "Kingston" }
{ country: "Norfolk Island", capital: "Kingston" }
{ country: "Saint Vincent and the Grenadines", capital: "Kingstown" }
{ country: "Democratic Republic of the Congo", capital: "Kinshasa" }
{ country: "Malaysia", capital: "Kuala Lumpur (official, legislative and royal)" }
{ country: "Malaysia", capital: "Putrajaya (administrative and judicial)" }
{ country: "Kuwait", capital: "Kuwait City" }
{ country: "Gabon", capital: "Libreville" }
{ country: "Malawi", capital: "Lilongwe" }
{ country: "Peru", capital: "Lima" }
{ country: "Portugal", capital: "Lisbon" }
{ country: "Slovenia", capital: "Ljubljana" }
{ country: "Togo", capital: "Lomé" }
{ country: "United Kingdom", capital: "London" }
{ country: "Angola", capital: "Luanda" }
{ country: "Zambia", capital: "Lusaka" }
{ country: "Luxembourg", capital: "Luxembourg" }
{ country: "Spain", capital: "Madrid" }
{ country: "Marshall Islands", capital: "Majuro" }
{ country: "Equatorial Guinea", capital: "Malabo" }
{ country: "Maldives", capital: "Malé" }
{ country: "Nicaragua", capital: "Managua" }
{ country: "Bahrain", capital: "Manama" }
{ country: "Philippines", capital: "Manila" }
{ country: "Mozambique", capital: "Maputo" }
{ country: "Saint Martin", capital: "Marigot" }
{ country: "Lesotho", capital: "Maseru" }
{ country: "Wallis and Futuna", capital: "Mata-Utu" }
{ country: "Swaziland", capital: "Mbabane (administrative)" }
{ country: "Swaziland", capital: "Lobamba (royal and legislative)" }
{ country: "Mexico", capital: "Mexico City" }
{ country: "Belarus", capital: "Minsk" }
{ country: "Somalia", capital: "Mogadishu" }
{ country: "Monaco", capital: "Monaco" }
{ country: "Liberia", capital: "Monrovia" }
{ country: "Uruguay", capital: "Montevideo" }
{ country: "Comoros", capital: "Moroni" }
{ country: "Russia", capital: "Moscow" }
{ country: "Oman", capital: "Muscat" }
{ country: "Kenya", capital: "Nairobi" }
{ country: "Bahamas", capital: "Nassau" }
{ country: "Burma", capital: "Naypyidaw" }
{ country: "Chad", capital: "N'Djamena" }
{ country: "India", capital: "New Delhi" }
{ country: "Palau", capital: "Ngerulmud" }
{ country: "Niger", capital: "Niamey" }
{ country: "Cyprus", capital: "Nicosia" }
{ country: "Northern Cyprus", capital: "Nicosia" }
{ country: "Mauritania", capital: "Nouakchott" }
{ country: "New Caledonia", capital: "Nouméa" }
{ country: "Tonga", capital: "Nukuʻalofa" }
{ country: "Greenland", capital: "Nuuk" }
{ country: "Aruba", capital: "Oranjestad" }
{ country: "Norway", capital: "Oslo" }
{ country: "Canada", capital: "Ottawa" }
{ country: "Burkina Faso", capital: "Ouagadougou" }
{ country: "American Samoa", capital: "Pago Pago" }
{ country: "Federated States of Micronesia", capital: "Palikir" }
{ country: "Panama", capital: "Panama City" }
{ country: "French Polynesia", capital: "Papeete" }
{ country: "Suriname", capital: "Paramaribo" }
{ country: "France", capital: "Paris" }
{ country: "Sint Maarten", capital: "Philipsburg" }
{ country: "Cambodia", capital: "Phnom Penh" }
{ country: "Montserrat", capital: "Plymouth (official)" }
{ country: "Montserrat", capital: "Brades Estate (de facto)", query: "Brades,+Montserrat" }
{ country: "Montenegro", capital: "Podgorica (official)" }
{ country: "Montenegro", capital: "Cetinje (seat of the President)" }
{ country: "Mauritius", capital: "Port Louis" }
{ country: "Papua New Guinea", capital: "Port Moresby" }
{ country: "Vanuatu", capital: "Port Vila" }
{ country: "Haiti", capital: "Port-au-Prince" }
{ country: "Trinidad and Tobago", capital: "Port of Spain" }
{ country: "Benin", capital: "Porto-Novo (official)" }
{ country: "Benin", capital: "Cotonou (de facto)" }
{ country: "Czech Republic", capital: "Prague" }
{ country: "Cape Verde", capital: "Praia" }
{ country: "South Africa", capital: "Pretoria (executive)" }
{ country: "South Africa", capital: "Bloemfontein (judicial)" }
{ country: "South Africa", capital: "Cape Town (legislative)" }
{ country: "Kosovo[g]", capital: "Pristina" }
{ country: "North Korea", capital: "Pyongyang" }
{ country: "Ecuador", capital: "Quito" }
{ country: "Morocco", capital: "Rabat" }
{ country: "Iceland", capital: "Reykjavík" }
{ country: "Latvia", capital: "Riga" }
{ country: "Saudi Arabia", capital: "Riyadh" }
{ country: "British Virgin Islands", capital: "Road Town" }
{ country: "Italy", capital: "Rome" }
{ country: "Dominica", capital: "Roseau" }
{ country: "Northern Mariana Islands", capital: "Saipan" }
{ country: "Costa Rica", capital: "San José" }
{ country: "Puerto Rico", capital: "San Juan" }
{ country: "San Marino", capital: "San Marino" }
{ country: "El Salvador", capital: "San Salvador" }
{ country: "Yemen", capital: "Sana'a" }
{ country: "Chile", capital: "Santiago (official)" }
{ country: "Chile", capital: "Valparaíso (legislative)" }
{ country: "Dominican Republic", capital: "Santo Domingo" }
{ country: "São Tomé and Príncipe", capital: "São Tomé" }
{ country: "Bosnia and Herzegovina", capital: "Sarajevo" }
{ country: "South Korea", capital: "Seoul" }
{ country: "Singapore", capital: "Singapore" }
{ country: "Macedonia", capital: "Skopje" }
{ country: "Bulgaria", capital: "Sofia" }
{ country: "Sri Lanka", capital: "Sri Jayawardenepura Kotte (official)" }
{ country: "Sri Lanka", capital: "Colombo (former capital; has some government offices)" }
{ country: "Grenada", capital: "St. George's" }
{ country: "Jersey", capital: "St. Helier" }
{ country: "Antigua and Barbuda", capital: "St. John's" }
{ country: "Guernsey", capital: "St. Peter Port" }
{ country: "Saint Pierre and Miquelon", capital: "St. Pierre" }
{ country: "Falkland Islands", capital: "Stanley" }
{ country: "Nagorno-Karabakh Republic", capital: "Stepanakert", query: "Stepanakert" }
{ country: "Sweden", capital: "Stockholm" }
{ country: "Bolivia", capital: "Sucre (constitutional)" }
{ country: "Bolivia", capital: "La Paz (administrative)" }
{ country: "Abkhazia", capital: "Sukhumi" }
{ country: "Fiji", capital: "Suva" }
{ country: "Taiwan", capital: "Taipei" }
{ country: "Estonia", capital: "Tallinn" }
{ country: "Kiribati", capital: "Tarawa Atoll" }
{ country: "Uzbekistan", capital: "Tashkent" }
{ country: "Georgia", capital: "Tbilisi (official)" }
{ country: "Georgia", capital: "Kutaisi (legislative)" }
{ country: "Honduras", capital: "Tegucigalpa" }
{ country: "Iran", capital: "Tehran" }
{ country: "Bhutan", capital: "Thimphu" }
{ country: "Albania", capital: "Tirana" }
{ country: "Transnistria", capital: "Tiraspol" }
{ country: "Japan", capital: "Tokyo" }
{ country: "Faroe Islands", capital: "Tórshavn" }
{ country: "Libya", capital: "Tripoli" }
{ country: "South Ossetia", capital: "Tskhinvali" }
{ country: "Tunisia", capital: "Tunis" }
{ country: "Mongolia", capital: "Ulaanbaatar" }
{ country: "Liechtenstein", capital: "Vaduz" }
{ country: "Malta", capital: "Valletta" }
{ country: "Anguilla", capital: "The Valley" }
{ country: "Vatican City", capital: "Vatican City" }
{ country: "Seychelles", capital: "Victoria" }
{ country: "Austria", capital: "Vienna" }
{ country: "Laos", capital: "Vientiane" }
{ country: "Lithuania", capital: "Vilnius", query: "Vilnius" }
{ country: "Poland", capital: "Warsaw" }
{ country: "United States", capital: "Washington" }
{ country: "New Zealand", capital: "Wellington" }
{ country: "Cocos (Keeling) Islands", capital: "West Island" }
{ country: "Curaçao", capital: "Willemstad" }
{ country: "Namibia", capital: "Windhoek" }
{ country: "Ivory Coast", capital: "Yamoussoukro (official)" }
{ country: "Ivory Coast", capital: "Abidjan (former capital; still has many government offices)" }
{ country: "Cameroon", capital: "Yaoundé" }
{ country: "Nauru", capital: "Yaren (de facto)" }
{ country: "Armenia", capital: "Yerevan" }
{ country: "Croatia", capital: "Zagreb" }
]
_NUM_CALLS_PER_INTERVAL = 10 # 一回のサイクルで呼び出すAPIコール数
_MAP_IMG_WIDTH = 1280 # 地図画像の幅
_MAP_IMG_HEIGHT = 930 # 地図画像の高さ
_EQUATOR_ON_IMG = 465 # 地図が層の赤道の位置 (上端から[px])
_CENTRAL_LONGITUDE_ON_IMG = 0 # 地図画像の中心の軽度
# ミラー図法から変換した際のY座標の最大値
_MILLER_CYLINDRICAL_PROJECTION_POS_Y_MAX = 5 / 4 * Math.log(Math.tan(1 / 4 * Math.PI + 2 / 5 * 90 / 180 * Math.PI))
constructor: ->
@$body = $ 'body'
@$pre = $('<pre>').appendTo @$body
@$current = $ '.current'
@$total = $ '.total'
# HTML上にJSON形式のデータを出力
displayData: ()=>
@data = project.MapData.COUNTRY_DATA
@numData = @data.length
@totalAPICallCount = Math.floor(@numData / _NUM_CALLS_PER_INTERVAL) + 1
@currentAPICallCount = 0
@$total.text @totalAPICallCount
@outputData = []
$.when.apply($, (for i in [0...@totalAPICallCount] then @appendDataPerInterval(i))).done =>
# すべてのデータ
log 'complete', @outputData
alert 'complete'
str = ''
for data in @outputData
# JSONの形で出力
str += """
{
"country": "#{data.country}",
"capital": "#{data.capital}",
"x": #{data.x},
"y": #{data.y}
},
"""
@$pre.text str
# サイクルごとのデータを取得
appendDataPerInterval: (index)=>
d = new $.Deferred()
start = index * _NUM_CALLS_PER_INTERVAL
end = Math.min start + _NUM_CALLS_PER_INTERVAL, @numData
setTimeout (=>
# APIをコールしてデータを追加
$.when.apply($, (for i in [start...end] then @appendData(@data[i]))).done =>
d.resolve()
@currentAPICallCount++
@$current.text @currentAPICallCount
), index * 2000
return d.promise()
# APIをコールして座標変換したものを出力用データに追加
appendData: (data)=>
country = data.country
capital = data.capital
regexp = new RegExp ' \(.*\)'
query = "#{capital.replace(regexp, '')},+#{country.replace(regexp, '')}".replace(/ /g, '+')
if data.query? then query = data.query
return $.getJSON "https://maps.googleapis.com/maps/api/geocode/json?address=#{query}&language=en&key=AIzaSyCRj5hoOWV05oaN5hFRtLmx5VFicAzzXXA"
.done (json)=>
# console.logに出力
log country, capital, json
# データがなければ終了
geocodeData = json.results
if geocodeData.length isnt 1
geocodeData = geocodeData.filter (item)-> return $.inArray('political', item.types) isnt -1
if geocodeData.length is 0
log query, country, capital, geocodeData
return
location = geocodeData[0].geometry.location
# X座標は(取得した軽度 - 画像の中心の軽度)を基準計算
x = location.lng - _CENTRAL_LONGITUDE_ON_IMG
# -180 < x < 180
if x < -180 then x += 360
# ピクセルへ変換
x = x / 360 * _MAP_IMG_WIDTH
# y座標を算出
y = 5 / 4 * Math.log(Math.tan(1 / 4 * Math.PI + 2 / 5 * location.lat / 180 * Math.PI)) / _MILLER_CYLINDRICAL_PROJECTION_POS_Y_MAX * _MAP_IMG_HEIGHT / 2
# データを追加
@outputData.push
country: country
capital: capital
x: x
y: y
このクラスのインスタンスを生成して、displayDataを実行しています。
※log関数(Math.logじゃないよ)はconsole.logをラップしている関数です。
ミラー図法で計算する上で、画像上の赤道の位置[px](_EQUATOR_ON_IMG)と画像の中心の経度(_CENTRAL_LONGITUDE_ON_IMG)が必要なのでその値もハードコーディングしています。
今回使用した地図の画像はグリニッジ天文台が中心の世界地図なので、_CENTRAL_LONGITUDE_ON_IMGは0です。
COUNTRY_DATAから国名、首都名で住所の文字列を生成し、2秒おきに10回のAPIコールが発生します。
addressパラメータに住所の文字列を渡しますが、"首都名, 国名"となるようにしています。ただし、スペースは"+"に変換しています。
APIをコールすると、文字列のみで検索しているので、多少のあいまいさを含むため、検索結果が複数返ってくる場合があります。
基本的にはデータの先頭を使用していますが、上記のクエリだけでは正しく検索できない場合もあったので、その場合はクエリを調整しています。
(COUNTRY_DATAの各要素の中に"query"という要素を保つ場合はこの値をaddressパラメータに使用。)
また、結果のフィルタリングもしています。首都を示すデータの場合は、データのtypes要素に"political"が含まれるらしいので、その条件で結果の配列にフィルタをかけています。
上記の調整でいい感じのデータが作れました。
あとは返ってきたデータに位置情報(緯度・経度)が含まれるので、その値を平面の世界地図の座標に変換します。
座標の以下の式を使用します。
λは経度、φは緯度です。この場合のx, yは画像の中心からの値です。
x座標はこの式だと角度のままなので、画像の大きさに合わせてピクセルの値に変換します。
# X座標は(取得した経度 - 画像の中心の経度)を基準計算 x = location.lng - _CENTRAL_LONGITUDE_ON_IMG # -180 < x < 180 if x < -180 then x += 360 # ピクセルへ変換 x = x / 360 * _MAP_IMG_WIDTH
y座標もこの式だと、φが90°の時が最大値、-90°の時が最小値のよくわからない値になるので、ピクセルに変換します。
ピクセルの値に変換する際に、φが90°の時の最大値が必要になるので、予め_MILLER_CYLINDRICAL_PROJECTION_POS_Y_MAXに入れておきます。
# ミラー図法から変換した際のY座標の最大値 _MILLER_CYLINDRICAL_PROJECTION_POS_Y_MAX = 5 / 4 * Math.log(Math.tan(1 / 4 * Math.PI + 2 / 5 * 90 / 180 * Math.PI))
# y座標を算出 y = 5 / 4 * Math.log(Math.tan(1 / 4 * Math.PI + 2 / 5 * location.lat / 180 * Math.PI)) / _MILLER_CYLINDRICAL_PROJECTION_POS_Y_MAX * _MAP_IMG_HEIGHT / 2
これで座標のデータが完成したので、jsonデータに保存しました。
あとはこのデータを使用して、実際に地図上に場所をマッピングしたデモは後編で。
