---
title: "GeneralFunction"
slug: "nearest"
updated: 2022-09-23T14:14:16Z
published: 2022-09-23T14:14:16Z
canonical: "docs.datajet.app/nearest"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datajet.app/llms.txt
> Use this file to discover all available pages before exploring further.

# NEAREST(LT, LN, TLT, TLN)

## Geo: NEAREST (LT, LN, TLT, TLN)

### Returns the row number of the nearest point in a lookup table of latitudes and longitudes

## Purpose

Use this function to:

- Identify the nearest lookup location to a set of coordinates
- Find nearest geographical place
- Create a continuous integer key that can be used to link to a lookup table

## Return Value

| Property | Value |
| --- | --- |
| **FieldType** | Integer |
| **FieldSize** | Continuous |
| **DataType** | Continuous |
| **DataSize** | Integer |

```shell
Example Return Value: 1 to N, where N is the number of rows in the lookup table
```

![Nearest_data](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/Nearest_data.PNG)

## Parameters

| Parameter | JSON | Description |
| --- | --- | --- |
| **Table** | “targetTable”: “MyTableName” | The target table on which the new field will be created |
| **Filter** | “dataset”: {DataSet_JSON} | Optional. If a filter is applied, records not in the filter DataSet will be returned as null. |
| **Function** | "function":"geo" | Geo |
| **Geo Function** | "p1": "NEAREST(LT,LN,TLT,TLN)" | NEAREST(LT,LN,TLT,TLN) |
| **LT** | “p2”: "lat" | Required. The field on the targetTable containing the latitude value. *Supports:* - **DataType:** Discrete/Continuous - **Field Type:** Double - **Fixed Value:** #nn.nnnnnnn |
| **LN** | “p3”: "lon" | Required. The field on the targetTable containing the longitude value *Supports:* - **DataType: Discrete/Continuous** - **Field Type: Double** - **Fixed Value:** #nn.nnnnnnn |
| **TLT** | “p4”: "worldcities.lat" | Required. The fully qualified column on the lookup table that contains latitude. *Supports:* - **DataType: Discrete/Continuous** - **Field Type: Double** - **Fixed Value:** #nn.nnnnnnn |
| **TLN** | “p5”:"worldcities.lng" | Required. The fully qualified column on the lookup table that contains longitude. *Supports:* - **DataType: Discrete/Continuous** - **Field Type: Double** - **Fixed Value:** #nn.nnnnnnn |

## JSON Sample

```json
{
  "method": "BuildBakedField",
  "project": "Model1",
  "targetTable": "BikePoints",
  "overwrite": true,
  "name": "Nearest",
  "function": "geo",
  "p1": "NEAREST(LT,LN,TLT,TLN)",
  "p2": "lat",
  "p3": "lon",
  "p4": "worldcities.lat",
  "p5": "worldcities.lng"
}
```

## Usage Notes

NEAREST returns an continuous integer key into the lookup table. Use this key to create a key to the lookup table, and then copy up specific data-points as required.

Example targetTable:

![targetTable](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/targetTable.PNG)

Example Lookup Table:

![LookupTable](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/LookupTable.PNG)

See Also:

- Distance(A, B, C, D)
- DIST2NEAREST(LT, LN, TLT, TLN)
- GMNearest, GMDIST2NEAREST
- [Copy Up](/v1/docs/copy-up)
- [Joins](/v1/docs/joins)

## Example

| Example | Details |
| --- | --- |
| **Description** | Obtain lookup of world city that is nearest to BikePoint |
| **Input** | - Table: = [BikePoint] - Function:= Geo - Filter: = [No Filter] - **Geo Function: = NEAREST(LT, LN, TLT, TLN)** - LT:= lat - LN:= lon - TLT:= worldcities.lat - TLN:= worldcities.lon - Name: =Nearest |
| **Sample** | ![NEAREST_Example](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/NEAREST_Example.PNG) |