docs-v2/content/flux/v0/stdlib/experimental/geo/groupbyarea.md

title	description	menu	weight	flux/v0/tags
geo.groupByArea() function	`geo.groupByArea()` groups rows by geographic area.	flux_v0_ref name parent identifier geo.groupByArea experimental/geo experimental/geo/groupByArea	201	transformations geotemporal

geo.groupByArea() groups rows by geographic area.

Area sizes are determined by the specified level. Each geographic area is assigned a unique identifier (the S2 cell ID token) which is stored in the newColumn. Results are grouped by newColumn.

Function type signature

(
    <-tables: stream[{A with s2_cell_id: string, lon: float, lat: float}],
    level: int,
    newColumn: string,
    ?s2cellIDLevel: int,
) => stream[B] where B: Record

{{% caption %}} For more information, see Function type signatures. {{% /caption %}}

Parameters

newColumn

({{< req >}}) Name of the new column for the unique identifier for each geographic area.

level

({{< req >}}) S2 Cell level used to determine the size of each geographic area.

s2cellIDLevel

S2 Cell level used in the s2_cell_id tag. Default is -1 (detects S2 cell level from the s2_cell_id tag).

tables

Input data. Default is piped-forward data (<-).

Examples

Group geotemporal data by geographic area

import "experimental/geo"

data
    |> geo.groupByArea(newColumn: "foo", level: 4)

{{< expand-wrapper >}} {{% expand "View example input and output" %}}

Input data

_time	*id	lat	lon	*s2_cell_id
2021-01-03T02:00:00Z	a213b	39.08433	-75.9978	89bc

_time	*id	lat	lon	*s2_cell_id
2021-01-01T00:00:00Z	a213b	41.01433	-70.7515	89e4

_time	*id	lat	lon	*s2_cell_id
2021-01-02T01:00:00Z	a213b	40.9228	-73.3527	89ec

Output data

*foo	_time	id	lat	lon	s2_cell_id
89b	2021-01-03T02:00:00Z	a213b	39.08433	-75.9978	89bc

*foo	_time	id	lat	lon	s2_cell_id
89f	2021-01-01T00:00:00Z	a213b	41.01433	-70.7515	89e4
89f	2021-01-02T01:00:00Z	a213b	40.9228	-73.3527	89ec

{{% /expand %}} {{< /expand-wrapper >}}