Studio provides a set of functions for working with geometries.

Function	Description
`buffer()`	Creates a buffer polygon surrounding a point on the map.
`bufferFeature()`	Creates a buffer polygon surrounding a GeoJSON Geometry feature.
`bufferH3()`	Creates a polygon surrounding an H3 cell.
`centroid()`	Returns the center point of a GeoJSON Geometry feature.
`latLngToPoint()`	Creates a GeoJSON Point from latitude/longitude coordinates.
`pointLat()`	Returns the latitude of a GeoJSON Point.
`pointLng()`	Returns the longitude of a GeoJSON Point.

buffer

Create buffer polygons surrounding each set of latitude/longitude coordinates.

Method

buffer(lat: number, lng: number, bufferDistance: number, distanceUnit?: string, pointsPerArc?: number): Feature

Parameters

Parameter	Type	Description
`lat`	`number`	Required. A column containing latitude coordinates.
`lng`	`number`	Required. A column containing longitude coordinates.
`bufferDistance`	`number`	Required. The length of the buffer surrounding the point.
`distanceUnit`	`string`	The distance unit to use for the buffer, either `Meter`/`Meters`, or `Mile`/`Miles` (not case-sensitive). Default: `Mile`
`pointsPerArc`	`number`	The number of points to create the rounded corner of the buffered shape. A higher number of points generates a smoother buffer corner. Default: `10`

Returns

Returns a GeoJSON feature buffer for each set of coordinates.

Example

Suppose lat and lng contain latitude and longitude coordinates, respectively.

Create a smoothed 40-meter buffer surrounding each point on the map:

buffer(lat, lng, 40, "meter", 40);

Left: pointPerArc = 10; Right: pointsPerArc = 40

bufferFeature

Create buffer polygons surrounding a set of GeoJSON features/objects, such as polygons or multi-polygons.

Method

bufferFeature(feature: Feature, bufferDistance: number, distanceUnit?: string, pointsPerArc?: number): Feature

Parameters

Parameter	Type	Description
`feature`	GeoJSON `feature`	Required. The name of the GeoJSON feature column to surround with buffer polygons.
`bufferDistance`	`number`	Required. The length of the buffer from the edge of each feature.
`distanceUnit`	`string`	The distance unit to use for the buffer, either `Meter`/`Meters`, or `Mile`/`Miles` (not case-sensitive). Default: `Mile`
`pointsPerArc`	`number`	The number of points to create the rounded corner of the buffered shape. A higher number of points generates a smoother buffer corner. Default: `10`

Returns

Returns a GeoJSON feature buffer for each existing GeoJSON feature.

Example

Suppose roads is a column containing a set of GeoJSON polygons representing roads.

Create a 50-meter buffer surrounding each road on the map:

bufferFeature(roads, 50, "Meter");

bufferH3

Create buffer polygons surrounding each H3 cell.

Method

bufferH3(h3: string, bufferDistance: number, distanceUnit?: string, pointsPerArc?: number): Feature

Parameters

Parameter	Type	Description
`h3`	`string`	Required. A column containing H3 cell strings to surround with buffer polygons.
`bufferDistance`	`number`	Required. The length of the buffer from the edge of each cell.
`distanceUnit`	`string`	The distance unit to use for the buffer, either `Meter`/`Meters`, or `Mile`/`Miles` (not case-sensitive). Default: `Mile`
`pointsPerArc`	`number`	The number of points to create the rounded corner of the buffered shape. A higher number of points generates a smoother buffer corner. Default: `10`

Returns

Returns a GeoJSON feature buffer for each H3 cell.

Example

Suppose h3 is a column containing H3 indexes.

Create a 2-mile buffer surrounding each H3 cell in h3:

bufferh3(h3, 2);

centroid

Get the centroid of a GeoJSON Geometry object. The geometry type could be Point/MultiPoint, LineString/MultiLineString, or Polygon/MultiPolygon. A geometry's geometric center of mass is computed and returned.

Method

centroid(geo: Feature): Feature<Point>

Parameters

Parameter	Type	Description
`geo`	GeoJSON Geometry feature/object or a WKT `string`.	Required. The column containing the polygons to derive centroid from.

Returns

Returns a GeoJSON Point feature for each polygon provided.

Example

Suppose there is a _geojson column in the dataset table.

Find the centroid for each GeoJSON Geometry feature/object in _geojson:

centroid(_geojson);

latLngToPoint

Creates a GeoJSON Point feature for each set of coordinates.

Method

latLngToPoint(lat: number, lng: number): Feature<Point>

Parameters

Parameter	Type	Description
`lat`	`number`	Required. A column containing latitude coordinates.
`lng`	`number`	Required. A column containing longitude coordinates.

Returns

Returns a GeoJSON Point feature for each set of coordinates.

Example

Suppose lat and lng contain latitude and longitude coordinates, respectively.

Create a GeoJSON Point feature for a set of coordinates:

latLngToPoint(lat, lng);

pointLat

Get the latitude value of a GeoJSON Point feature.

Method

pointLat(pt: Feature<Point>): number

Parameters

Parameter	Type	Description
`pt`	A GeoJSON Point feature/object	Required. A column containing GeoJSON Points to derive latitude from.

Returns

Returns a numeric latitude value for each Point feature.

Example

Suppose there is a _geojson column in the dataset table.

Retrieve the latitude values for each GeoJSON Point:

pointLat(_geojson);

pointLng

Get the longitude value of a GeoJSON Point feature.

Method

pointLng(pt: Feature<Point>): number

Parameters

Parameter	Type	Description
`pt`	A GeoJSON Point feature/object	Required. A column containing GeoJSON Points to derive longitude from.

Returns

Returns a numeric longitude value for each Point feature.

Example

Suppose there is a _geojson column in the dataset table.

Retrieve the longitude values for each GeoJSON Point:

pointLng(_geojson);

Note: pointLat() and pointLng() can be used to create new latitude and longitude columns for a Point layer.