This is a single value metrics aggregation that calculates the average of the numeric values that are extracted from the aggregated documents.
POST /index/_search?
{
"aggs" : {
"avd_value" : { "avg" : { "field" : "name_of_field" } }
}
}
The above aggregation computes the average grade over all documents. The aggregation type is avg and the field setting defines the numeric field of the documents the average will be computed on. The above will return the following:
{
...
"aggregations": {
"avg_value": {
"value": 75.0
}
}
}
The name of the aggregation (avg_grade above) also serves as the key by which the aggregation result can be retrieved from the returned response.