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

<!------------------------------------------------------------------------------

IMPORTANT: This page was generated from comments in the Flux source code. Any
edits made directly to this page will be overwritten the next time the
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To make updates to this documentation, update the function comments above the
function definition in the Flux source code:

https://github.com/influxdata/flux/blob/master/stdlib/experimental/geo/geo.flux#L924-L948

Contributing to Flux: https://github.com/influxdata/flux#contributing
Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md

------------------------------------------------------------------------------->

`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

```js
(
    <-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](/flux/v0/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](https://s2geometry.io/resources/s2cell_statistics.html)
used to determine the size of each geographic area.



### s2cellIDLevel

[S2 Cell level](https://s2geometry.io/resources/s2cell_statistics.html)
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

```js
import "experimental/geo"

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

```

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{{% 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 >}}