Geovisualization Developer's Guide


When you use this function in a query, it returns the top number of entries in the specified column in the specified dataset, based on the value specified in the parameters params.

For more information on using query functions and operators in a REST API request, see Queries. For an end-to-end description of how to create a query, see Creating a Query.

The codeblock example below filters the Region column in the earthquake dataset, whose {DATASET_ID} is 90af668484394fa782cc103409cafe39, for the first 10 (ten) entries.

  "version": 0.3,
  "dataset": "90af668484394fa782cc103409cafe39",
  "namespace": {
    "top_hundred": {
      "source": ["Region"],
      "apply": [{
        "fn": "top_n", 
        "type": "transform",   
        "params": [100]
  "metrics": ["top_hundred"],

When you submit the above request, the response includes an HTTP status code and a JSON response body.

For more information on the HTTP status codes, see HTTP Status Codes.

For more information on the elements in the JSON structure in the response body, see Query.