# Map Match

## Match GPS coordinates to the road network

`client.MapMatch.Match(ctx, body) (*MapMatchResult, error)`

**post** `/api/v1/map-match`

Match GPS coordinates to the road network

### Parameters

- `body MapMatchMatchParams`

  - `MapMatchRequest param.Field[MapMatchRequest]`

    GPS trace to snap to the road network. Provide an array of coordinate objects representing the GPS points. Maximum 50 points per request.

### Returns

- `type MapMatchResult struct{…}`

  Map matching result as a GeoJSON FeatureCollection. Each Feature is a snapped tracepoint. The top-level `matchings` array contains the matched sub-routes connecting consecutive tracepoints.

  - `Features []MapMatchResultFeature`

    Snapped tracepoint Features in input order

    - `Geometry GeoJsonGeometry`

      GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints.

      - `Coordinates GeoJsonGeometryCoordinatesUnion`

        Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc.

        - `type GeoJsonGeometryCoordinatesPoint []float64`

          [longitude, latitude] or [longitude, latitude, elevation]

        - `type GeoJsonGeometryCoordinatesLineStringOrMultiPoint [][]float64`

          Array of [lng, lat] positions

        - `type GeoJsonGeometryCoordinatesPolygonOrMultiLineString [][][]float64`

          Array of linear rings / line strings

        - `type GeoJsonGeometryCoordinatesMultiPolygon [][][][]float64`

          Array of polygons

      - `Type GeoJsonGeometryType`

        Geometry type

        - `const GeoJsonGeometryTypePoint GeoJsonGeometryType = "Point"`

        - `const GeoJsonGeometryTypeLineString GeoJsonGeometryType = "LineString"`

        - `const GeoJsonGeometryTypePolygon GeoJsonGeometryType = "Polygon"`

        - `const GeoJsonGeometryTypeMultiPoint GeoJsonGeometryType = "MultiPoint"`

        - `const GeoJsonGeometryTypeMultiLineString GeoJsonGeometryType = "MultiLineString"`

        - `const GeoJsonGeometryTypeMultiPolygon GeoJsonGeometryType = "MultiPolygon"`

    - `Properties MapMatchResultFeaturesProperties`

      - `DistanceM float64`

        Distance from the original GPS point to the snapped point in meters

      - `EdgeID int64`

        Road edge ID the point was snapped to

      - `MatchingsIndex int64`

        Index into the `matchings` array indicating which matching sub-route this point belongs to

      - `Name string`

        Road name at the snapped point

      - `Original []float64`

        Original GPS coordinate as [lng, lat]

      - `WaypointIndex int64`

        Index of this tracepoint in the original `coordinates` array

    - `Type MapMatchResultFeaturesType`

      - `const MapMatchResultFeaturesTypeFeature MapMatchResultFeaturesType = "Feature"`

  - `Matchings []map[string, unknown]`

    Matched sub-routes. Each matching connects a contiguous sequence of tracepoints that could be matched to roads.

  - `Type MapMatchResultType`

    - `const MapMatchResultTypeFeatureCollection MapMatchResultType = "FeatureCollection"`

### Example

```go
package main

import (
  "context"
  "fmt"

  "github.com/plazafyi/plaza-go"
  "github.com/plazafyi/plaza-go/option"
)

func main() {
  client := githubcomplazafyiplazago.NewClient(
    option.WithAPIKey("My API Key"),
  )
  mapMatchResult, err := client.MapMatch.Match(context.TODO(), githubcomplazafyiplazago.MapMatchMatchParams{
    MapMatchRequest: githubcomplazafyiplazago.MapMatchRequestParam{
      Coordinates: githubcomplazafyiplazago.F([]githubcomplazafyiplazago.MapMatchRequestCoordinateParam{githubcomplazafyiplazago.MapMatchRequestCoordinateParam{
        Lat: githubcomplazafyiplazago.F(48.856600),
        Lng: githubcomplazafyiplazago.F(2.352200),
      }, githubcomplazafyiplazago.MapMatchRequestCoordinateParam{
        Lat: githubcomplazafyiplazago.F(48.857000),
        Lng: githubcomplazafyiplazago.F(2.353000),
      }, githubcomplazafyiplazago.MapMatchRequestCoordinateParam{
        Lat: githubcomplazafyiplazago.F(48.857500),
        Lng: githubcomplazafyiplazago.F(2.354000),
      }}),
    },
  })
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", mapMatchResult.Features)
}
```

#### Response

```json
{
  "features": [
    {
      "geometry": {
        "coordinates": [
          2.3522,
          48.8566
        ],
        "type": "Point"
      },
      "properties": {
        "distance_m": 0,
        "edge_id": 0,
        "matchings_index": 0,
        "name": "name",
        "original": [
          0,
          0
        ],
        "waypoint_index": 0
      },
      "type": "Feature"
    }
  ],
  "matchings": [
    {
      "foo": "bar"
    }
  ],
  "type": "FeatureCollection"
}
```

## Domain Types

### Map Match Request

- `type MapMatchRequest struct{…}`

  GPS trace to snap to the road network. Provide an array of coordinate objects representing the GPS points. Maximum 50 points per request.

  - `Coordinates []MapMatchRequestCoordinate`

    GPS coordinates to match, in order of travel (max 50 points)

    - `Lat float64`

      Latitude in decimal degrees (-90 to 90)

    - `Lng float64`

      Longitude in decimal degrees (-180 to 180)

  - `Radiuses []float64`

    Search radius per coordinate in meters. Must have the same length as `coordinates` or be omitted entirely. Default: 50m per point.

### Map Match Result

- `type MapMatchResult struct{…}`

  Map matching result as a GeoJSON FeatureCollection. Each Feature is a snapped tracepoint. The top-level `matchings` array contains the matched sub-routes connecting consecutive tracepoints.

  - `Features []MapMatchResultFeature`

    Snapped tracepoint Features in input order

    - `Geometry GeoJsonGeometry`

      GeoJSON Geometry object per RFC 7946. Coordinates use [longitude, latitude] order. 3D coordinates [lng, lat, elevation] are used for elevation endpoints.

      - `Coordinates GeoJsonGeometryCoordinatesUnion`

        Coordinates array. Nesting depth varies by geometry type: Point = [lng, lat], LineString = [[lng, lat], ...], Polygon = [[[lng, lat], ...], ...], etc.

        - `type GeoJsonGeometryCoordinatesPoint []float64`

          [longitude, latitude] or [longitude, latitude, elevation]

        - `type GeoJsonGeometryCoordinatesLineStringOrMultiPoint [][]float64`

          Array of [lng, lat] positions

        - `type GeoJsonGeometryCoordinatesPolygonOrMultiLineString [][][]float64`

          Array of linear rings / line strings

        - `type GeoJsonGeometryCoordinatesMultiPolygon [][][][]float64`

          Array of polygons

      - `Type GeoJsonGeometryType`

        Geometry type

        - `const GeoJsonGeometryTypePoint GeoJsonGeometryType = "Point"`

        - `const GeoJsonGeometryTypeLineString GeoJsonGeometryType = "LineString"`

        - `const GeoJsonGeometryTypePolygon GeoJsonGeometryType = "Polygon"`

        - `const GeoJsonGeometryTypeMultiPoint GeoJsonGeometryType = "MultiPoint"`

        - `const GeoJsonGeometryTypeMultiLineString GeoJsonGeometryType = "MultiLineString"`

        - `const GeoJsonGeometryTypeMultiPolygon GeoJsonGeometryType = "MultiPolygon"`

    - `Properties MapMatchResultFeaturesProperties`

      - `DistanceM float64`

        Distance from the original GPS point to the snapped point in meters

      - `EdgeID int64`

        Road edge ID the point was snapped to

      - `MatchingsIndex int64`

        Index into the `matchings` array indicating which matching sub-route this point belongs to

      - `Name string`

        Road name at the snapped point

      - `Original []float64`

        Original GPS coordinate as [lng, lat]

      - `WaypointIndex int64`

        Index of this tracepoint in the original `coordinates` array

    - `Type MapMatchResultFeaturesType`

      - `const MapMatchResultFeaturesTypeFeature MapMatchResultFeaturesType = "Feature"`

  - `Matchings []map[string, unknown]`

    Matched sub-routes. Each matching connects a contiguous sequence of tracepoints that could be matched to roads.

  - `Type MapMatchResultType`

    - `const MapMatchResultTypeFeatureCollection MapMatchResultType = "FeatureCollection"`