Тепловые карты

The heatmapTiles endpoint provides pollen-related heatmaps through tile overlay. A tile overlay is a collection of image tiles that can be displayed on top of Google Maps. Each image tile is 256 x 256 pixels.

The tile overlay is a grid assembled from a collection of tiles, each assigned ( X , Y ) coordinates. The tile with coordinates (0,0) is always at the northwest corner of the map. The X values increase from west to east, while the Y values increase from north to south.

The zoom level determines how large or small the contents of a map appear in a map view. The tile grid size is determined by scaling the X and Y coordinates exponentially by the zoom level.

gridSizeX = XzoomLevel
gridSizeY = YzoomLevel

For example, at a zoom level of 2, the world map is represented using a 4 x 4 matrix, for a total of 16 tiles.

The following image shows a TREE_UPI heatmap of the entire world, sectioned into tiles that can be accessed at a zoom level of 2.

A heatmap of the entire world as a 4 by 4 grid.

See Map and Tile coordinates for additional details.

You can request current pollen heatmap tiles using the heatmapTiles endpoint by sending an HTTP GET request to:

https://pollen.googleapis.com/v1/mapTypes/TYPE/heatmapTiles/Z/X/Y?key=YOUR_API_KEY

About the heatmap endpoint

Все параметры, перечисленные ниже, необходимы для успешного запроса:

  • KEY : Your application's API key. This key identifies your application for purposes of quota management. Learn how to get a key .
  • TYPE : Тип возвращаемой тепловой карты. См. допустимые значения .
  • Z : Zoom level that determines how large or small the contents of a map appear in a map view. Allowed values are 0-16, where a value of 0 displays the entire world in a single tile.
  • X , Y : The tile coordinates relatively to the north east corner (0,0). X values increase from west to east and Y values increase from north to south. Coordinates must be valid for the specified zoom level. For example, if you set the zoom level to 2 and request a tile at coordinates (10,10), the API returns an error.

Пример запроса тепловой карты

На изображении выше показана тепловая карта TREE_UPI с уровнем масштабирования 2, а также координаты каждой плитки. The following example uses the heatmapTiles endpoint to request the tile at coordinates (2,1):

https://pollen.googleapis.com/v1/mapTypes/TREE_UPI/heatmapTiles/2/2/1?key=YOUR_API_KEY

Плитка отображается в виде изображения, которое можно наложить на карту:

An example of a heatmap tile using the TREE_UPI map.

Дополнительную информацию о наложении плиток поверх карты по умолчанию см. в разделе Типы наложенных карт .