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Use Clustering - quadbin

This section describes how to retrieve features from Data Hub inside a tile in a clustered form. Two different clustering modes, "hexbin" and "quadbin", are available.

  • "quadbin" - gives the amount of features in tiles and subtiles. Purpuse is to give a fast overview on dataset locations on lower zoom levels. The quadbins corresponds to the webmercator tiling scheme.
  • "hexbin" - gives the amount of feature in a hexagonal tiling. Beside the amount of the features per hexbin it provides statistics (min, max, avg, median) on a user-defined property.

quadbin

Fire data

Get clustered Features in a tile

The quadbin algorithm takes the geometry input from the request (e.g. quadkey / bbox..) and does estimated count on the features contained in the space. This clustering mode works also for very large spaces and can be used for getting an overview where data is geolocated in a given space. Furthermore, a property filter on one property is applicable.

There are several parameters needed by the quadbin algorithm. You can use one property filter in combination.

Request

Try in Swagger

GET /spaces/{spaceId}/tile/{type}/{tileId}?clustering=quadbin&clustering.relativeResolution={aNumber}&clustering.countmode={cmode}

The following clustering related parameters can be passed

Parameter Type Mandatory Meaning
relativeResolution Number NO integer, The quad resolution [0,4]
noBuffer Boolean NO do not place a buffer around quad polygons, default: false
countmode String NO [real, estimated, mixed]

real = real feature counts.
Best accuracy, but slow.
Not recommended for big result sets

estimated = estimated feature counts.
Low accuracy, but very fast
Recommended for big result sets

mixed (default) = estimated feature counts combined with real ones.
If the estimation is low a real count gets applied. Fits to the
most use cases

Response

{
    "type": "FeatureCollection",
    "features": [
        {
            "type": "Feature",
            "properties": {
                "qk": "12002323333",     // tile quadkey
                "xyz": "(639,1071,11)",  // tile row/col/level 
                "count": 30393,          // count of features in tile 
                "estimated": true,       
                "total_count": 33521484,      // total feature count in related space
                "equipartition_count": 511    // total_count/#Nr_Of_All_Level_Tiles
            },
            "geometry": {...}  
        },
        ......
        ......
        {
            "type": "Feature",
            "type": "Feature",
            "properties": {
                "qk": "12002323331",
                "xyz": "(638,1071,11)", 
                    ....
            },
            "geometry": {...}
        }
    ]
}