Eine Choroplethenkarte (Intensitätskarte) ist eine thematische Karte, bei der Verwaltungsgebiete gemäß einem Datenwert eingefärbt bzw. schattiert werden. Mit einer google.maps.FeatureStyleFunction können Sie den Stil einer Karte basierend auf einem Dataset definieren, wobei jedem Verwaltungsbereich ein numerischer Wertebereich zugeordnet ist. Die folgende Beispielkarte zeigt eine Choroplethenkarte mit Bevölkerungsdaten der einzelnen Bundesstaaten in den USA.
In diesem Beispiel bestehen die Daten aus einem Array von Schlüssel/Wert-Paaren, bei dem der Anzeigename eines Bundesstaates mit einem numerischen Wert für die Bevölkerung verknüpft ist. Über maps.FeatureStyleFunction wird die Farbe für die einzelnen Regionen je nach Wert im Array unter bestimmten Bedingungen festgelegt.
TypeScript
featureLayer.style = featureStyleFunctionOptions => {
const placeFeature = featureStyleFunctionOptions.feature as google.maps.PlaceFeature;
const population = states[placeFeature.placeId];
let fillColor;
// Specify colors using any of the following:
// * Named ('green')
// * Hexadecimal ('#FF0000')
// * RGB ('rgb(0, 0, 255)')
// * HSL ('hsl(60, 100%, 50%)')
if (population < 2000000) {
fillColor = 'green'
} else if (population < 5000000) {
fillColor = 'red'
} else if (population < 10000000) {
fillColor = 'blue'
} else if (population < 40000000) {
fillColor = 'yellow'
}
return {
fillColor,
fillOpacity: 0.5
}
}
JavaScript
featureLayer.style = (featureStyleFunctionOptions) => {
const placeFeature = featureStyleFunctionOptions.feature;
const population = states[placeFeature.placeId];
let fillColor;
// Specify colors using any of the following:
// * Named ('green')
// * Hexadecimal ('#FF0000')
// * RGB ('rgb(0, 0, 255)')
// * HSL ('hsl(60, 100%, 50%)')
if (population < 2000000) {
fillColor = "green";
} else if (population < 5000000) {
fillColor = "red";
} else if (population < 10000000) {
fillColor = "blue";
} else if (population < 40000000) {
fillColor = "yellow";
}
return {
fillColor,
fillOpacity: 0.5,
};
};
Vollständiges Codebeispiel
TypeScript
async function initMap() {
// Request needed libraries.
const { Map } = await google.maps.importLibrary("maps") as google.maps.MapsLibrary;
const map = new Map(document.getElementById('map') as HTMLElement, {
center: { lat: 40.76, lng: -101.64 },
zoom: 5,
// In the cloud console, configure this Map ID with a style that enables the
// "Administrative Area Level 1" feature layer.
mapId: '7ba16be0c9375fa7',
});
const featureLayer = map.getFeatureLayer(google.maps.FeatureType.ADMINISTRATIVE_AREA_LEVEL_1);
featureLayer.style = featureStyleFunctionOptions => {
const placeFeature = featureStyleFunctionOptions.feature as google.maps.PlaceFeature;
const population = states[placeFeature.placeId];
let fillColor;
// Specify colors using any of the following:
// * Named ('green')
// * Hexadecimal ('#FF0000')
// * RGB ('rgb(0, 0, 255)')
// * HSL ('hsl(60, 100%, 50%)')
if (population < 2000000) {
fillColor = 'green'
} else if (population < 5000000) {
fillColor = 'red'
} else if (population < 10000000) {
fillColor = 'blue'
} else if (population < 40000000) {
fillColor = 'yellow'
}
return {
fillColor,
fillOpacity: 0.5
}
}
// Population data by state.
const states = {
"ChIJdf5LHzR_hogR6czIUzU0VV4": 5039877, // Alabama
"ChIJG8CuwJzfAFQRNduKqSde27w": 732673, // Alaska
"ChIJaxhMy-sIK4cRcc3Bf7EnOUI": 7276316, // Arizona
"ChIJYSc_dD-e0ocR0NLf_z5pBaQ": 3025891, // Arkansas
"ChIJPV4oX_65j4ARVW8IJ6IJUYs": 39237836, // California
"ChIJt1YYm3QUQIcR_6eQSTGDVMc": 5812069, // Colorado
"ChIJpVER8hFT5okR5XBhBVttmq4": 3605597, // Connecticut
"ChIJO9YMTXYFx4kReOgEjBItHZQ": 1003384, // Delaware
"ChIJvypWkWV2wYgR0E7HW9MTLvc": 21781128, // Florida
"ChIJV4FfHcU28YgR5xBP7BC8hGY": 10799566, // Georgia
"ChIJBeB5Twbb_3sRKIbMdNKCd0s": 1441553, // Hawaii
"ChIJ6Znkhaj_WFMRWIf3FQUwa9A": 1900923, // Idaho
"ChIJGSZubzgtC4gRVlkRZFCCFX8": 12671469, // Illinois
"ChIJHRv42bxQa4gRcuwyy84vEH4": 6805985, // Indiana
"ChIJGWD48W9e7ocR2VnHV0pj78Y": 3193079, // Iowa
"ChIJawF8cXEXo4cRXwk-S6m0wmg": 2934582, // Kansas
"ChIJyVMZi0xzQogR_N_MxU5vH3c": 4509394, // Kentucky
"ChIJZYIRslSkIIYRA0flgTL3Vck": 4624047, // Louisiana
"ChIJ1YpTHd4dsEwR0KggZ2_MedY": 1372247, // Maine
"ChIJ35Dx6etNtokRsfZVdmU3r_I": 6165129, // Maryland
"ChIJ_b9z6W1l44kRHA2DVTbQxkU": 6984723, // Massachussetts
"ChIJEQTKxz2qTE0Rs8liellI3Zc": 10050811, // Michigan
"ChIJmwt4YJpbWE0RD6L-EJvJogI": 5707390, // Minnesota
"ChIJGdRK5OQyKIYR2qbc6X8XDWI": 2949965, // Mississippi
"ChIJfeMiSNXmwIcRcr1mBFnEW7U": 6168187, // Misssouri
"ChIJ04p7LZwrQVMRGGwqz1jWcfU": 1104271, // Montana
"ChIJ7fwMtciNk4cRxArzDwyQJ6E": 1963692, // Nebraska
"ChIJcbTe-KEKmYARs5X8qooDR88": 3143991, // Nevada
"ChIJ66bAnUtEs0wR64CmJa8CyNc": 1388992, // New Hampshire
"ChIJn0AAnpX7wIkRjW0_-Ad70iw": 9267130, // New Jersey
"ChIJqVKY50NQGIcRup41Yxpuv0Y": 2115877, // New Mexico
"ChIJqaUj8fBLzEwRZ5UY3sHGz90": 19835913, // New York
"ChIJgRo4_MQfVIgRGa4i6fUwP60": 10551162, // North Carolina
"ChIJY-nYVxKD11IRyc9egzmahA0": 774948, // North Dakota
"ChIJwY5NtXrpNogRFtmfnDlkzeU": 11780017, // Ohio
"ChIJnU-ssRE5rIcRSOoKQDPPHF0": 3986639, // Oklahoma
"ChIJVWqfm3xuk1QRdrgLettlTH0": 4246155, // Oregon
"ChIJieUyHiaALYgRPbQiUEchRsI": 12964056, // Pennsylvania
"ChIJD9cOYhQ15IkR5wbB57wYTh4": 1095610, // Rhode Island
"ChIJ49ExeWml-IgRnhcF9TKh_7k": 5190705, // South Carolina
"ChIJpTjphS1DfYcRt6SGMSnW8Ac": 895376, // South Dakota
"ChIJA8-XniNLYYgRVpGBpcEgPgM": 6975218, // Tennessee
"ChIJSTKCCzZwQIYRPN4IGI8c6xY": 29527941, // Texas
"ChIJzfkTj8drTIcRP0bXbKVK370": 3337975, // Utah
"ChIJ_87aSGzctEwRtGtUNnSJTSY": 645570, // Vermont
"ChIJzbK8vXDWTIgRlaZGt0lBTsA": 8642274, // Virginia
"ChIJ-bDD5__lhVQRuvNfbGh4QpQ": 7738692, // Washington
"ChIJRQnL1KVUSogRQzrN3mjHALs": 1782959, // West Virginia
"ChIJr-OEkw_0qFIR1kmG-LjV1fI": 5895908, // Wisconsin
"ChIJaS7hSDTiXocRLzh90nkisCY": 578803, // Wyoming
};
}
initMap();
JavaScript
async function initMap() {
// Request needed libraries.
const { Map } = await google.maps.importLibrary("maps");
const map = new Map(document.getElementById("map"), {
center: { lat: 40.76, lng: -101.64 },
zoom: 5,
// In the cloud console, configure this Map ID with a style that enables the
// "Administrative Area Level 1" feature layer.
mapId: "7ba16be0c9375fa7",
});
const featureLayer = map.getFeatureLayer(
google.maps.FeatureType.ADMINISTRATIVE_AREA_LEVEL_1,
);
featureLayer.style = (featureStyleFunctionOptions) => {
const placeFeature = featureStyleFunctionOptions.feature;
const population = states[placeFeature.placeId];
let fillColor;
// Specify colors using any of the following:
// * Named ('green')
// * Hexadecimal ('#FF0000')
// * RGB ('rgb(0, 0, 255)')
// * HSL ('hsl(60, 100%, 50%)')
if (population < 2000000) {
fillColor = "green";
} else if (population < 5000000) {
fillColor = "red";
} else if (population < 10000000) {
fillColor = "blue";
} else if (population < 40000000) {
fillColor = "yellow";
}
return {
fillColor,
fillOpacity: 0.5,
};
};
// Population data by state.
const states = {
"ChIJdf5LHzR_hogR6czIUzU0VV4": 5039877, // Alabama
"ChIJG8CuwJzfAFQRNduKqSde27w": 732673, // Alaska
"ChIJaxhMy-sIK4cRcc3Bf7EnOUI": 7276316, // Arizona
"ChIJYSc_dD-e0ocR0NLf_z5pBaQ": 3025891, // Arkansas
"ChIJPV4oX_65j4ARVW8IJ6IJUYs": 39237836, // California
"ChIJt1YYm3QUQIcR_6eQSTGDVMc": 5812069, // Colorado
"ChIJpVER8hFT5okR5XBhBVttmq4": 3605597, // Connecticut
"ChIJO9YMTXYFx4kReOgEjBItHZQ": 1003384, // Delaware
"ChIJvypWkWV2wYgR0E7HW9MTLvc": 21781128, // Florida
"ChIJV4FfHcU28YgR5xBP7BC8hGY": 10799566, // Georgia
"ChIJBeB5Twbb_3sRKIbMdNKCd0s": 1441553, // Hawaii
"ChIJ6Znkhaj_WFMRWIf3FQUwa9A": 1900923, // Idaho
"ChIJGSZubzgtC4gRVlkRZFCCFX8": 12671469, // Illinois
"ChIJHRv42bxQa4gRcuwyy84vEH4": 6805985, // Indiana
"ChIJGWD48W9e7ocR2VnHV0pj78Y": 3193079, // Iowa
"ChIJawF8cXEXo4cRXwk-S6m0wmg": 2934582, // Kansas
"ChIJyVMZi0xzQogR_N_MxU5vH3c": 4509394, // Kentucky
"ChIJZYIRslSkIIYRA0flgTL3Vck": 4624047, // Louisiana
"ChIJ1YpTHd4dsEwR0KggZ2_MedY": 1372247, // Maine
"ChIJ35Dx6etNtokRsfZVdmU3r_I": 6165129, // Maryland
"ChIJ_b9z6W1l44kRHA2DVTbQxkU": 6984723, // Massachussetts
"ChIJEQTKxz2qTE0Rs8liellI3Zc": 10050811, // Michigan
"ChIJmwt4YJpbWE0RD6L-EJvJogI": 5707390, // Minnesota
"ChIJGdRK5OQyKIYR2qbc6X8XDWI": 2949965, // Mississippi
"ChIJfeMiSNXmwIcRcr1mBFnEW7U": 6168187, // Misssouri
"ChIJ04p7LZwrQVMRGGwqz1jWcfU": 1104271, // Montana
"ChIJ7fwMtciNk4cRxArzDwyQJ6E": 1963692, // Nebraska
"ChIJcbTe-KEKmYARs5X8qooDR88": 3143991, // Nevada
"ChIJ66bAnUtEs0wR64CmJa8CyNc": 1388992, // New Hampshire
"ChIJn0AAnpX7wIkRjW0_-Ad70iw": 9267130, // New Jersey
"ChIJqVKY50NQGIcRup41Yxpuv0Y": 2115877, // New Mexico
"ChIJqaUj8fBLzEwRZ5UY3sHGz90": 19835913, // New York
"ChIJgRo4_MQfVIgRGa4i6fUwP60": 10551162, // North Carolina
"ChIJY-nYVxKD11IRyc9egzmahA0": 774948, // North Dakota
"ChIJwY5NtXrpNogRFtmfnDlkzeU": 11780017, // Ohio
"ChIJnU-ssRE5rIcRSOoKQDPPHF0": 3986639, // Oklahoma
"ChIJVWqfm3xuk1QRdrgLettlTH0": 4246155, // Oregon
"ChIJieUyHiaALYgRPbQiUEchRsI": 12964056, // Pennsylvania
"ChIJD9cOYhQ15IkR5wbB57wYTh4": 1095610, // Rhode Island
"ChIJ49ExeWml-IgRnhcF9TKh_7k": 5190705, // South Carolina
"ChIJpTjphS1DfYcRt6SGMSnW8Ac": 895376, // South Dakota
"ChIJA8-XniNLYYgRVpGBpcEgPgM": 6975218, // Tennessee
"ChIJSTKCCzZwQIYRPN4IGI8c6xY": 29527941, // Texas
"ChIJzfkTj8drTIcRP0bXbKVK370": 3337975, // Utah
"ChIJ_87aSGzctEwRtGtUNnSJTSY": 645570, // Vermont
"ChIJzbK8vXDWTIgRlaZGt0lBTsA": 8642274, // Virginia
"ChIJ-bDD5__lhVQRuvNfbGh4QpQ": 7738692, // Washington
"ChIJRQnL1KVUSogRQzrN3mjHALs": 1782959, // West Virginia
"ChIJr-OEkw_0qFIR1kmG-LjV1fI": 5895908, // Wisconsin
"ChIJaS7hSDTiXocRLzh90nkisCY": 578803, // Wyoming
};
}
initMap();
CSS
/*
* Always set the map height explicitly to define the size of the div element
* that contains the map.
*/
#map {
height: 100%;
}
/*
* Optional: Makes the sample page fill the window.
*/
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
HTML
<html>
<head>
<title>Choropleth Map</title>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script type="module" src="./index.js"></script>
</head>
<body>
<div id="map"></div>
<!-- prettier-ignore -->
<script>(g=>{var h,a,k,p="The Google Maps JavaScript API",c="google",l="importLibrary",q="__ib__",m=document,b=window;b=b[c]||(b[c]={});var d=b.maps||(b.maps={}),r=new Set,e=new URLSearchParams,u=()=>h||(h=new Promise(async(f,n)=>{await (a=m.createElement("script"));e.set("libraries",[...r]+"");for(k in g)e.set(k.replace(/[A-Z]/g,t=>"_"+t[0].toLowerCase()),g[k]);e.set("callback",c+".maps."+q);a.src=`https://maps.${c}apis.com/maps/api/js?`+e;d[q]=f;a.onerror=()=>h=n(Error(p+" could not load."));a.nonce=m.querySelector("script[nonce]")?.nonce||"";m.head.append(a)}));d[l]?console.warn(p+" only loads once. Ignoring:",g):d[l]=(f,...n)=>r.add(f)&&u().then(()=>d[l](f,...n))})
({key: "AIzaSyB41DRUbKWJHPxaFjMAwdrzWzbVKartNGg", v: "weekly"});</script>
</body>
</html>