How to calculate max in sth-comet?

Question

sth-comet offers the possibility of calculate max, min and other functions, as described [here]https://github.com/telefonicaid/fiware-sth-comet/blob/master/doc/manuals/aggregated-data-retrieval.md

But I have tried different types and it doesn't gives the aggregated result.

A simplified version of my entity (I use the attribute temperature in this example) is:

{
     "id": "Beach:27",
     "type": "Beach",
     "flag": {
       "type": "Property",
       "value": "Verde"
     },
     "temperature": {
       "type": "Number",
       "value": 45
     }

I have make this query that should give the maximum value:

http://{{sth-comet}}/STH/v1/contextEntities/type/Beach/id/Beach:27/attributes/temperature?aggrMethod=max&hLimit=100&hOffset=0

but the result is not the max but all the changes of the attribute:

{
    "contextResponses": [
        {
            "contextElement": {
                "attributes": [
                    {
                        "name": "temperature",
                        "values": [
                            {
                                "recvTime": "2019-09-15T18:32:18.166Z",
                                "attrType": "Number",
                                "attrValue": "43"
                            },
                            {
                                "recvTime": "2019-09-15T18:32:24.645Z",
                                "attrType": "Number",
                                "attrValue": "44"
                            },
                            {
                                "recvTime": "2019-09-15T18:32:28.931Z",
                                "attrType": "Number",
                                "attrValue": "45"
                            }
                        ]
                    }
                ],
                "id": "Beach:27",
                "isPattern": false,
                "type": "Beach"
            },
            "statusCode": {
                "code": "200",
                "reasonPhrase": "OK"
            }
        }
    ]
}

Which is the type that the property must have to work correctly? I tried "Number", "integer","string", "Property" but I don't obtain the "max" value.

Thank you for your time

score 1 · Answer 1 · edited Sep 16 '19 at 08:30

The requests for aggregated time series context information can use the following query parameters:

aggrMethod: (mandatory) You can use max, min, sum and sum2.
aggrPeriod: (mandatory) you can use month, day, hour, minute and second.
dateFrom and dateTo: (optional) to range of data you query.

In your request you don't put the mandatory parameter (aggrPeriod). Can you test something else:
( http://{{sth-comet}}/STH/v1/contextEntities/type/Beach/id/Beach:27/attributes/temperature?aggrMethod=max&aggrPeriod=second&dateFrom=2019-09-15T00:00:00.000Z&dateTo=2019-09-15T23:59:59.999Z )

https://github.com/telefonicaid/fiware-sth-comet/blob/master/doc/manuals/aggregated-data-retrieval.md

How to calculate max in sth-comet?

1 Answers1