geo_geohash_neighbors()

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Applies to: ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel

Calculates Geohash neighbors.

Read more about geohash.

Syntax

geo_geohash_neighbors(geohash)

Learn more about syntax conventions.

Parameters

Name Type Required Description
geohash string ✔️ A geohash value as it was calculated by geo_point_to_geohash(). The geohash string must be between 1 and 18 characters.

Returns

An array of Geohash neighbors. If the Geohash is invalid, the query produces a null result.

Examples

The following example calculates Geohash neighbors.

print neighbors = geo_geohash_neighbors('sunny')

Output

neighbors
["sunnt","sunpj","sunnx","sunpn","sunnv","sunpp","sunnz","sunnw"]

The following example calculates an array of input Geohash with its neighbors.

let geohash = 'sunny';
print cells = array_concat(pack_array(geohash), geo_geohash_neighbors(geohash))

Output

cells
["sunny","sunnt","sunpj","sunnx","sunpn","sunnv","sunpp","sunnz","sunnw"]

The following example calculates Geohash polygons GeoJSON geometry collection.

let geohash = 'sunny';
print cells = array_concat(pack_array(geohash), geo_geohash_neighbors(geohash))
| mv-expand cells to typeof(string)
| project polygons = geo_geohash_to_polygon(cells)
| summarize arr = make_list(polygons)
| project geojson = bag_pack("type", "Feature","geometry", bag_pack("type", "GeometryCollection", "geometries", arr), "properties", bag_pack("name", "polygons"))

Output

geojson
{"type": "Feature","geometry": {"type": "GeometryCollection","geometries": [
{"type":"Polygon","coordinates":[[[42.451171875,23.6865234375],[42.4951171875,23.6865234375],[42.4951171875,23.73046875],[42.451171875,23.73046875],[42.451171875,23.6865234375]]]},
{"type":"Polygon","coordinates":[[[42.4072265625,23.642578125],[42.451171875,23.642578125],[42.451171875,23.6865234375],[42.4072265625,23.6865234375],[42.4072265625,23.642578125]]]},
{"type":"Polygon","coordinates":[[[42.4072265625,23.73046875],[42.451171875,23.73046875],[42.451171875,23.7744140625],[42.4072265625,23.7744140625],[42.4072265625,23.73046875]]]},
{"type":"Polygon","coordinates":[[[42.4951171875,23.642578125],[42.5390625,23.642578125],[42.5390625,23.6865234375],[42.4951171875,23.6865234375],[42.4951171875,23.642578125]]]},
{"type":"Polygon","coordinates":[[[42.451171875,23.73046875],[42.4951171875,23.73046875],[42.4951171875,23.7744140625],[42.451171875,23.7744140625],[42.451171875,23.73046875]]]},
{"type":"Polygon","coordinates":[[[42.4072265625,23.6865234375],[42.451171875,23.6865234375],[42.451171875,23.73046875],[42.4072265625,23.73046875],[42.4072265625,23.6865234375]]]},
{"type":"Polygon","coordinates":[[[42.4951171875,23.73046875],[42.5390625,23.73046875],[42.5390625,23.7744140625],[42.4951171875,23.7744140625],[42.4951171875,23.73046875]]]},
{"type":"Polygon","coordinates":[[[42.4951171875,23.6865234375],[42.5390625,23.6865234375],[42.5390625,23.73046875],[42.4951171875,23.73046875],[42.4951171875,23.6865234375]]]},
{"type":"Polygon","coordinates":[[[42.451171875,23.642578125],[42.4951171875,23.642578125],[42.4951171875,23.6865234375],[42.451171875,23.6865234375],[42.451171875,23.642578125]]]}]},
"properties": {"name": "polygons"}}

The following example calculates polygon unions that represent Geohash and its neighbors.

let h3cell = 'sunny';
print cells = array_concat(pack_array(h3cell), geo_geohash_neighbors(h3cell))
| mv-expand cells to typeof(string)
| project polygons = geo_geohash_to_polygon(cells)
| summarize arr = make_list(polygons)
| project polygon = geo_union_polygons_array(arr)

Output

polygon
{"type":"Polygon","coordinates":[[[42.4072265625,23.642578125],[42.451171875,23.642578125],[42.4951171875,23.642578125],[42.5390625,23.642578125],[42.5390625,23.686523437500004],[42.5390625,23.730468750000004],[42.5390625,23.7744140625],[42.4951171875,23.7744140625],[42.451171875,23.7744140625],[42.407226562499993,23.7744140625],[42.4072265625,23.73046875],[42.4072265625,23.6865234375],[42.4072265625,23.642578125]]]}

The following example returns true because of the invalid Geohash token input.

print invalid = isnull(geo_geohash_neighbors('a'))

Output

invalid
1