opensearch-docs-cn/_aggregations/bucket/geo-distance.md

160 lines
3.8 KiB
Markdown
Raw Normal View History

---
layout: default
title: Geodistance
parent: Bucket aggregations
grand_parent: Aggregations
nav_order: 70
redirect_from:
- /query-dsl/aggregations/bucket/geo-distance/
---
# Geodistance aggregations
The `geo_distance` aggregation groups documents into concentric circles based on distances from an origin `geo_point` field.
It's the same as the `range` aggregation, except that it works on geo locations.
For example, you can use the `geo_distance` aggregation to find all pizza places within 1 km of you. The search results are limited to the 1 km radius specified by you, but you can add another result found within 2 km.
You can only use the `geo_distance` aggregation on fields mapped as `geo_point`.
A point is a single geographical coordinate, such as your current location shown by your smart-phone. A point in OpenSearch is represented as follows:
```json
{
"location": {
"type": "point",
"coordinates": {
"lat": 83.76,
"lon": -81.2
}
}
}
```
You can also specify the latitude and longitude as an array `[-81.20, 83.76]` or as a string `"83.76, -81.20"`
This table lists the relevant fields of a `geo_distance` aggregation:
Field | Description | Required
:--- | :--- |:---
`field` | Specify the geopoint field that you want to work on. | Yes
`origin` | Specify the geopoint that's used to compute the distances from. | Yes
`ranges` | Specify a list of ranges to collect documents based on their distance from the target point. | Yes
`unit` | Define the units used in the `ranges` array. The `unit` defaults to `m` (meters), but you can switch to other units like `km` (kilometers), `mi` (miles), `in` (inches), `yd` (yards), `cm` (centimeters), and `mm` (millimeters). | No
`distance_type` | Specify how OpenSearch calculates the distance. The default is `sloppy_arc` (faster but less accurate), but can also be set to `arc` (slower but most accurate) or `plane` (fastest but least accurate). Because of high error margins, use `plane` only for small geographic areas. | No
The syntax is as follows:
```json
{
"aggs": {
"aggregation_name": {
"geo_distance": {
"field": "field_1",
"origin": "x, y",
"ranges": [
{
"to": "value_1"
},
{
"from": "value_2",
"to": "value_3"
},
{
"from": "value_4"
}
]
}
}
}
}
```
This example forms buckets from the following distances from a `geo-point` field:
- Fewer than 10 km
- From 10 to 20 km
- From 20 to 50 km
- From 50 to 100 km
- Above 100 km
```json
GET opensearch_dashboards_sample_data_logs/_search
{
"size": 0,
"aggs": {
"position": {
"geo_distance": {
"field": "geo.coordinates",
"origin": {
"lat": 83.76,
"lon": -81.2
},
"ranges": [
{
"to": 10
},
{
"from": 10,
"to": 20
},
{
"from": 20,
"to": 50
},
{
"from": 50,
"to": 100
},
{
"from": 100
}
]
}
}
}
}
```
{% include copy-curl.html %}
#### Example response
```json
...
"aggregations" : {
"position" : {
"buckets" : [
{
"key" : "*-10.0",
"from" : 0.0,
"to" : 10.0,
"doc_count" : 0
},
{
"key" : "10.0-20.0",
"from" : 10.0,
"to" : 20.0,
"doc_count" : 0
},
{
"key" : "20.0-50.0",
"from" : 20.0,
"to" : 50.0,
"doc_count" : 0
},
{
"key" : "50.0-100.0",
"from" : 50.0,
"to" : 100.0,
"doc_count" : 0
},
{
"key" : "100.0-*",
"from" : 100.0,
"doc_count" : 14074
}
]
}
}
}
```