Issue with small number as value ie 1.222e-11 or 0.00000000001222

[konstantinosGombakis]

I have a strange issue. I have the following json as payload:

[{
    "id": "urn:ngsi-ld:test_small_number",
    "type": "test",
    "Category1": {
        "type": "Property",
        "value": 1.222e-11,
        "observedAt": "2024-01-11T10:00:07.446Z"
    },
    "Category2": {
        "type": "Property",
        "value": 0.00000000001222,
        "observedAt": "2024-01-11T10:00:07.446Z"
    },
    "Category3": {
        "type": "Property",
        "value": "0.00000000001222",
        "observedAt": "2024-01-11T10:00:07.446Z"
    }
}]

The data (Category1 and Category2) are saved OK (as double) in the mongoDB

when i request the data from the Orion-LD i get 0 for the Category1 and 2:

{
  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context-v1.6.jsonld",
  "id": "urn:ngsi-ld:test_small_number",
  "type": "test",
  "Category1": {
    "type": "Property",
    "value": **0**,
    "observedAt": "2024-01-11T10:00:07.446Z"
  },
  "Category2": {
    "type": "Property",
    "value": **0**,
    "observedAt": "2024-01-11T10:00:07.446Z"
  },
  "Category3": {
    "type": "Property",
    "value": "0.00000000001222",
    "observedAt": "2024-01-11T10:00:07.446Z"
  }
}

Is these a normal operation, so i have to send small numbers as strings?

[kzangeli]

Is these a normal operation, so i have to send small numbers as strings

Yeah, sorry about that. A CPU isn't really apt to deal with floating point numbers.
I often see things like 1.45 being converted to 1.44999999999999999.
Only thing I could really do about it would be to store the floating point both as a string and a floating point. Use the floating point value for comparisons and the "exact" string value for responses. But, I haven't implemented that, sorry.
Did consider it but never got down to really implement it.

I'd propose to change the "unit" - use for example microseconds instead of seconds, things like that.