热图
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根据您的偏好保存内容并对其进行分类。
heatmapTiles 端点通过图块叠加层提供与空气质量相关的热图。图块叠加层是一组可显示在 Google 地图顶部的 PNG 图片图块。每个图片块的大小为 256 x 256 像素。
热图功能块简介
图块叠加层是由一组图块组成的网格，每个图块都分配有 (X,Y) 坐标。
坐标为 (0,0) 的图块始终位于地图的西北角。X 值从西向东增加，而 Y 值从北向南增加。
zoom level 决定了地图视图中地图内容的大小。图块网格大小是通过按缩放级别以指数方式缩放 X 和 Y 坐标来确定的。
gridSizeX = XzoomLevel
gridSizeY = YzoomLevel
例如，在缩放级别为 2 时，世界地图使用 4x4 矩阵表示，总共有 16 个图块。缩放级别还决定了坐标允许的最大值。
下图显示了缩放级别为 2 的 US_AQI 热图，以及每个图块的坐标：
如需了解详情，请参阅地图和图块坐标。
关于热图端点
热力图图块由一个字节数组表示，其中包含作为 PNG 图片的图块数据。您可以使用 heatmapTiles 端点，通过向以下网址发送 HTTP GET 请求来请求当前空气质量热力图图块：
https://airquality.googleapis.com/v1/mapTypes/TYPE/heatmapTiles/Z/X/Y?key=YOUR_API_KEY
请求中需要包含所有请求参数：
TYPE - 要返回的热图类型。请参阅允许的值。
Z - 缩放级别，用于确定地图视图中地图内容的大小。允许的值为 0-16，其中值 0 表示在单个图块中显示整个世界。
X、Y - 要检索的图块的坐标，相对于西北角 (0,0)。X 值从西向东增加，Y 值从北向南增加。
图块坐标必须对指定的缩放级别有效。例如，如果您将缩放级别设置为 2，并请求坐标为 10,10 的图块，则 API 会返回错误。
YOUR_API_KEY - 您应用的 API 密钥。此密钥用于标识您的应用，以便进行配额管理。如需了解详情，请参阅获取密钥。
热图请求示例
上图显示了缩放级别为 2 的 US_AQI 热图，以及每个图块的坐标。以下示例使用 heatmapTiles 端点从热力图中请求坐标为 0,1 的图块：
https://airquality.googleapis.com/v1/mapTypes/US_AQI/heatmapTiles/2/0/1?key=YOUR_API_KEY
相应板块显示如下：
如需详细了解如何在默认地图上叠加图块，请参阅叠加地图类型。
如未另行说明，那么本页面中的内容已根据知识共享署名 4.0 许可获得了许可，并且代码示例已根据 Apache 2.0 许可获得了许可。有关详情，请参阅 Google 开发者网站政策。Java 是 Oracle 和/或其关联公司的注册商标。
最后更新时间 (UTC)：2025-08-31。
[null,null,["最后更新时间 (UTC)：2025-08-31。"],[[["\u003cp\u003eThe \u003ccode\u003eheatmapTiles\u003c/code\u003e endpoint delivers air quality heatmaps as a tile overlay, which is a collection of PNG images displayed on top of a Google Map.\u003c/p\u003e\n"],["\u003cp\u003eEach tile within the overlay has specific (X, Y) coordinates, with (0,0) at the northwest corner and increasing values eastward (X) and southward (Y), determined by the zoom level.\u003c/p\u003e\n"],["\u003cp\u003eThe zoom level (0-16) controls the map's scale and the tile grid size, with higher zoom levels showing more detailed areas.\u003c/p\u003e\n"],["\u003cp\u003eTo request a heatmap tile, you need to provide the heatmap type, zoom level (Z), tile coordinates (X, Y), and your API key in the request URL.\u003c/p\u003e\n"],["\u003cp\u003eYou can overlay these heatmap tiles on top of the default map using methods described in the provided documentation for a comprehensive air quality visualization.\u003c/p\u003e\n"]]],[],null,["The\n[`heatmapTiles`](/maps/documentation/air-quality/reference/rest/v1/mapTypes.heatmapTiles/lookupHeatmapTile)\nendpoint provides air quality related heatmaps through a tile overlay. A tile\noverlay is a collection of PNG image tiles that can be displayed on top of a\nGoogle Maps. Each image tile is (256 x 256 pixels).\n\nAbout heatmap tiles\n\nThe tile overlay is a grid assembled from a collection of tiles,\neach assigned (`X`,`Y`) coordinates.\nThe tile with coordinates (0,0) is always at the northwest corner\nof the map. The `X` values increase from west to east,\nwhile the `Y` values increase from north to south.\n\nThe `zoom level` determines how large or small the contents of a map appear in a\nmap view. The tile grid size is determined by scaling the `X` and `Y`\ncoordinates exponentially by the zoom level. \n\n```text\ngridSizeX = XzoomLevel\ngridSizeY = YzoomLevel\n```\n\nFor example, at a zoom level of 2, the world map is represented using a 4 x 4\nmatrix, for a total of 16 tiles. The zoom also determines what is the max value\nallowed for the coordinates.\n\nThe following image shows a `US_AQI` heatmap with a zoom level of 2,\nalong with the coordinates of each tile:\n\nSee [Map and Tile coordinates](/maps/documentation/javascript/coordinates)\nfor additional details.\n\nAbout the heatmap endpoint\n\nA heatmap tile is represented by a bytes array containing the tile data as a PNG\nimage. You request current air quality heatmap tiles using the\n[`heatmapTiles`](/maps/documentation/air-quality/reference/rest/v1/mapTypes.heatmapTiles/lookupHeatmapTile)\nendpoint by sending an HTTP GET request to: \n\n```html\nhttps://airquality.googleapis.com/v1/mapTypes/TYPE/heatmapTiles/Z/X/Y?key=YOUR_API_KEY\n```\n\nAll request parameters are required in a request:\n\n- `TYPE` - The type heatmap to return. See [allowed\n values](/maps/documentation/air-quality/reference/rest/v1/mapTypes.heatmapTiles/lookupHeatmapTile#maptype).\n\n- `Z` - Zoom level that determines how large or small the contents of a map\n appear in a map view. Allowed values are 0-16, where a value of 0 displays\n the entire world in a single tile.\n\n- `X`,`Y` - The coordinates of the tile to retrieve, relative to the north\n west corner (0,0). `X` values are increasing from west to east and `Y`\n values are increasing from north to south.\n\n Tile coordinates have to be valid for the specified zoom level.\n For example, if you set the zoom level to 2, and request a tile at\n coordinates of 10,10, the API returns an error.\n- `YOUR_API_KEY` - Your application's API key. This key identifies your\n application for purposes of quota management. For more information, see [get\n a key](/maps/documentation/air-quality/get-api-key).\n\nExample heatmap request\n\nThe image above shows a `US_AQI` heatmap with a zoom level of 2,\nalong with the coordinates of each tile. The following example uses the\n`heatmapTiles` endpoint to request the tile at coordinates 0,1 from the\nheatmap: \n\n```html\nhttps://airquality.googleapis.com/v1/mapTypes/US_AQI/heatmapTiles/2/0/1?key=YOUR_API_KEY\n```\n\nThe tile appears as:\n\nFor more information on overlaying tiles on top of the default map, see\n[Overlay Map Types](/maps/documentation/javascript/examples/maptype-overlay)."]]
