我正在尝试使用地图 API 查找特定区域内的 POI 数量。有人建议我使用诺基亚或 Yelp API，但我正在努力弄清楚如何开始这个项目。
兴趣点的实际类型并不重要，在这种情况下都是相关的。如果有人对这些地图 API 有任何经验并且知道我应该看什么，或者对我开始有用的示例，我将非常感激！
谢谢
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首先要看的是相关 API 的开发者文档站点。对于诺基亚 API，您将查看JavaScript 文档或RESTful Places API，对于 Yelp，请尝试http://www.yelp.com/developers/下的链接 （免责声明 - 我个人不使用 Yelp）
有许多示例使用API 资源管理器中的 Nokia Place api进行操作并在屏幕上查看结果。
这里有几个有用的例子可以帮助你入门
Nokia Places API 和 Yelp API 都是本地搜索 API - 换句话说，它们总是回答“我在哪里可以找到Y附近的X？”的问题，因此在他们的数据库中查找POI 的总数并不是一项现实的任务（因为许多 POI 将被认为与搜索位置无关，您可以做的是查找特定位置内 POI 的密度。
下面的代码最初会显示柏林市中心的书店，但如果你改变地图的焦点，它也会在其他城镇找到书店。您需要获取自己的免费应用程序 ID 和令牌才能使其正常工作。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<!--
Example from Nokia Maps API Playground, for more information visit http://api.maps.nokia.com
-->
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="X-UA-Compatible" content="IE=7; IE=EmulateIE9"/>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Nokia Maps API Example: Search by category</title>
<meta name="description" content="Search by category"/>
<meta name="keywords" content="search, services, places, category"/>
<!-- For scaling content for mobile devices, setting the viewport to the width of the device-->
<meta name=viewport content="width=device-width, height=device-height, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"/>
<!-- By default we add ?with=all to load every package available, it's better to change this parameter to your use case. Options ?with=maps|positioning|places|placesdata|directions|datarendering|all -->
<script type="text/javascript" charset="UTF-8" src="http://api.maps.nokia.com/2.2.3/jsl.js?with=all"></script>
<!-- JavaScript for example container (NoteContainer & Logger) -->
<style type="text/css">
html {
overflow:hidden;
}
body {
margin: 0;
padding: 0;
overflow: hidden;
width: 100%;
height: 100%;
position: absolute;
}
#mapContainer {
width: 80%;
height: 80%;
left: 0;
top: 0;
position: absolute;
}
#progress {
width: 80%;
height: 10%;
left: 0;
top: 80%;
position: absolute;
}
#buttons {
width: 80%;
height: 10%;
left: 0;
top: 90%;
position: absolute;
}
</style>
</head>
<body>
<div id="mapContainer"></div>
<div id="progress"></div>
<div id="buttons">
<a onClick="searchByCategory( map.center, 'bookshop' );return false;" href="#">Find Bookshops</a>
</div>
<script type="text/javascript" id="exampleJsSource">
/* Set authentication token and appid
* WARNING: this is a demo-only key
* please register on http://api.developer.nokia.com/
* and obtain your own developer's API key
*/
nokia.Settings.set("appId", "YOUR APP_ID");
nokia.Settings.set("authenticationToken", "YOUR TOKEN");
// Get the DOM node to which we will append the map
var mapContainer = document.getElementById("mapContainer");
// Create a map inside the map container DOM node
var map = new nokia.maps.map.Display(mapContainer, {
// Initial center and zoom level of the map
center: [52.51, 13.4],
zoomLevel: 10,
components: [
new nokia.maps.map.component.Behavior()
]
});
var searchManager = nokia.places.search.manager,
resultSet;
var searchCat;
var maxDistance = 0;
// Function for receiving search results from places search and process them
var processResults = function (data, requestStatus, requestId) {
var i, len, locations, marker;
if (requestStatus == "OK") {
// The function findPlaces() and reverseGeoCode() of return results in slightly different formats
locations = data.results ? data.results.items : [data.location];
// We check that at least one location has been found
if (locations.length > 0) {
// Remove results from previous search from the map
if (resultSet) map.objects.remove(resultSet);
// Convert all found locations into a set of markers
resultSet = new nokia.maps.map.Container();
for (i = 0, len = locations.length; i < len; i++) {
marker = new nokia.maps.map.StandardMarker(locations[i].position, { text: i+1 });
resultSet.objects.add(marker);
if (locations[i].distance > maxDistance){
maxDistance = locations[i].distance;
}
}
// Next we add the marker(s) to the map's object collection so they will be rendered onto the map
map.objects.add(resultSet);
// We zoom the map to a view that encapsulates all the markers into map's viewport
map.zoomTo(resultSet.getBoundingBox(), false);
progressUiElt.innerHTML = locations.length + " places found in the '" + searchCat + "' category within " + maxDistance + "m of "+ data.search.location.address.city ;
} else {
alert("Your search produced no results!");
}
} else {
alert("The search request failed");
}
};
// Binding of DOM elements to several variables so we can install event handlers.
var progressUiElt = document.getElementById("progress");
searchByCategory = function(searchCenter , category){
// Make a place search request
searchCat = category;
progressUiElt.innerHTML = "Looking for places in the '" + category + "' category...'";
searchManager.findPlacesByCategory({
category: category,
onComplete: processResults,
searchCenter: searchCenter,
limit: 100,
});
}
// Search for Bookshops in Berlin
searchByCategory( new nokia.maps.geo.Coordinate(52.51, 13.4), "bookshop" );
</script>
</body>
</html>
所以你可以看到柏林有 100 多家书店，但波茨坦只有 37 家。
于 2013-01-16T10:03:05.830 回答