Find existing locations

A find location analysis resulting in a new layer with parks 150 meters from a bike route.

What is a find existing locations analysis?

A find existing location analysis is the process of selecting and copying features that satisfy one or more SQL and/or spatial expressions. To execute the analysis, use the spatial analysis service and the FindExistingLocations operation.

find existing locations

Real-world examples of this analysis include the following:

  • Finding neighborhoods within a specified distance from schools or police stations.
  • Selecting specific points of interest within a larger dataset.
  • Finding road access that cannot be on or within view of a protected area.

How to perform a find location analysis

The general steps to performing a find existing locations analysis are as follows:

  1. Review the parameters for the FindExistingLocations operation.
  2. Determine if you would like the results as a feature collection (dynamic) or hosted feature layer (stored).
  3. Send a request to get the spatial analysis service URL.
  4. Execute a job request with the following URL and parameters:
    • URL: https://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/FindExistingLocations/submitJob
    • Parameters:
      • expressions: The SQL or spatial relation to select a subset of the data.
      • inputLayers: The feature collection(s) or hosted feature layer(s) from which you want to extract features.
      • outputName: A string representing the name of the hosted feature layer to reutrn with the results.
  5. Check the status.
  6. Get the output layer results.

To see examples using ArcGIS API for Python, ArcGIS REST JS, and the ArcGIS REST API, go to Examples below.

URL request

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http://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer/FindExistingLocations/submitJob?<parameters>

Required parameters

NameDescriptionExamples
fThe format of the data returned.f=json f=pjson
tokenAn OAuth 2.0 access token. Learn how to get an access token in Security and authentication.token=<ACCESS_TOKEN>
inputLayersThe point, polyline, or polygon feature data that will be used to construct the query.[{"url":"https://services.arcgis.com/nSZVuSZjHpEZZbRo/arcgis/rest/services/OSM_POI/FeatureServer/0","name":"OpenStreetMap - Points of interest (bèta) - Punten"}]
expressionsThe SQL or spatial query.[{"operator":"","layer":0,"where":"service = 'Eten en Drinken'"}]

Key parameters

NameDescriptionExamples
outputNameA string representing the name of the hosted feature layer to return with the results. NOTE: If you do not include this parameter, the results are returned as a feature collection (JSON).{"serviceProperties": {"name": "<SERVICE_NAME>"}}
contextA bounding box or output spatial reference for the analysis."extent":{"xmin:", "ymin:", "xmax:", "ymax:"}

Examples

Find neighborhoods (spatial query)

This example uses the FindExistingLocations operation to construct a spatial query that selects and returns all the neighborhoods within a half mile of a police station.

For the analysis, the inputLayers value is the Police stations and San Francisco Neighborhoods hosted feature layers. The expression value is: SF Neighborhoods within a distance of 0.5 Miles from Police Stations.

Find existing locations using a spatial query to return neighborhoods within 0.5 miles of police stations.

APIs

ArcGIS API for PythonArcGIS API for PythonArcGIS REST JS
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from arcgis import GIS
from arcgis.features.analysis import find_existing_locations

portal = GIS(username="<USERNAME>", password="<PASSWORD>")


police_stations = "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/Police_Stations/FeatureServer/0"

neighborhoods = "https://services3.arcgis.com/GVgbJbqm8hXASVYi/arcgis/rest/services/SF_Neighborhoods/FeatureServer/0"

results = find_existing_locations(
    input_layers=[neighborhoods, police_stations],
    expressions=[
        {
            "operator": "",
            "layer": 0,
            "selectingLayer": 1,
            "spatialRel": "withinDistance",
            "distance": 0.5,
            "units": "Miles",
        }
    ],
    #Outputs results as a hosted service.
    output_name="Find locations results"
)


result_features = results.layers[0].query()

print(
    f"Find existing features returned {len(result_features.features)} new records"
)

Service requests

Request
HTTPHTTPcURL
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POST arcgis.com/sharing/rest/portals/self HTTP/1.1
Content-Type: application/x-www-form-urlencoded

&f=json
&token=<ACCESS_TOKEN>
Response (JSON)
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{
  "helperServices": {
    // Other parameters
    "analysis": {
      "url": "https://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer"
    },
    "geoenrichment": {
      "url": "https://geoenrich.arcgis.com/arcgis/rest/services/World/GeoenrichmentServer"
    }
  }
}

Find hotels (SQL query)

This example uses the FindExistingLocations operation to construct a SQL query that selects and returns the restaurants within the OpenStreetMap-Points of interest (bèta) hosted layer.

For the analysis, the inputLayers value is the OpenStreetMap-Points of interest (bèta) hosted layer. The expression value is: "where":"service = 'Hotels en Pensions'".

Find existing locations using a SQL query to return hotels in Amsterdam.

APIs

ArcGIS API for PythonArcGIS API for PythonArcGIS REST JS
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from arcgis import GIS
from arcgis.features.analysis import find_existing_locations

portal = GIS(username="<USERNAME>", password="<PASSWORD>")



osm_points_of_interest = "https://services.arcgis.com/nSZVuSZjHpEZZbRo/arcgis/rest/services/OSM_POI/FeatureServer/0"

results = find_existing_locations(
    input_layers=[osm_points_of_interest],
    expressions=[
        {"operator": "", "layer": 0, "where": "POI-laag = 'Hotels en Pensions'"}
    ],
   #Outputs results as a hosted feature layer.
    output_name="Find locations results",
    context={
        "extent": {
            "xmin": 568547.4926900844,
            "ymin": 6816058.336549545,
            "xmax": 570749.8345676091,
            "ymax": 6817610.963686628,
            "spatialReference": {"wkid": 102100, "latestWkid": 3857},
        }
    },
)

result_features = results.layers[0].query()

print(
    f"Find existing features returned {len(result_features.features)} new records"
)

Service requests

Request
HTTPHTTPcURL
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POST arcgis.com/sharing/rest/portals/self HTTP/1.1
Content-Type: application/x-www-form-urlencoded

&f=json
&token=<ACCESS_TOKEN>
Response (JSON)
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{
  "helperServices": {
    // Other parameters
    "analysis": {
      "url": "https://<YOUR_ANALYSIS_SERVICE>/arcgis/rest/services/tasks/GPServer"
    },
    "geoenrichment": {
      "url": "https://geoenrich.arcgis.com/arcgis/rest/services/World/GeoenrichmentServer"
    }
  }
}

Tutorials

Learn how to perform related analyses interactively with Map Viewer and programmatically with ArcGIS API for Python, ArcGIS REST JS, and ArcGIS REST API.

Services

Spatial analysis service

Process spatial datasets to discover relationships and patterns.

API support

Full supportPartial supportNo support
  • 1. Access with geoprocessing task
  • 2. Access via ArcGIS REST JS

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