I’m using time series or single stat to display angle values in the range 0/360.
When the angle varies around the 0, then the mean value calculated by the grafana is wrong.
I’m using grafana with influxdb as data source.

Is there a way to make it calculate the average properly?
I guess a modulo 360 is the solution but I’m struggling right now.

Hi @grant2
Here is the query:
for time series:
SELECT mean(“value”) FROM “XXX” WHERE $timeFilter GROUP BY time($__interval) fill(null)
and then using the panel options to calculate the display min/max/mean.

Single stat:
SELECT “value” FROM “XXX” WHERE $timeFilter
and selecting the mean in the panel option:

I’m not using influx data explorer.
I’m a Grafana rookie…
Tried to search the community but didn’t find any topic about that subject.
Thanks

yes, the data is correct
it is the mean calculation that is wrong because it is a angle 0-360

also, for the display, i’d like to avoid the jumps from 0 to 360, as it is a continuons angle, as if 1 was displayed as 361. that’s why I was talking about the MOD.

Can you explain the above? For example, looking at these 5 points from your data:

Are you trying to calculate the mean over all 5 data points? Or perhaps the mean between two consecutive data points? I can see that the 358 value is going to skew the mean, but I am still not clear what Grafana is doing wrong (if anything).

if the dataset was not an angle, the mean calculation by grafana would be OK.
but as it is an angle betwen 0 and 360, it needs some “calculation”.
That’s why I was thinking of the modulo, but not sure how to implement it in the query.

If yes, then I kinda doubt Grafana or InfluxQL is going to be the tool to use here, but it’s all do-able using Flux or some other scripting that can be done on the angle values before ingesting into InfluxDB.

1.) You are mixing single stat with time series panel - both need different approach.
2.) Calculating avg in the singlestat panel from already aggregated values SELECT mean(“value”) FROM “XXX” WHERE $timeFilter GROUP BY time($__interval) fill(null) is math disaster - because result is not avg of whole set
3.) How smooth is the result depends on time aggregation. Don’t use magic $_interval variable, but define own value (variable) there, which will fit your expectations. It will be different if query returns 1min aggregation or 15min aggregation, e.g.: SELECT mean(“value”) FROM “XXX” WHERE $timeFilter GROUP BY time(1ml) fill(null)
vs SELECT mean(“value”) FROM “XXX” WHERE $timeFilter GROUP BY time(15m) fill(null)

Avg is just SELECT mean(“value”) FROM “XXX” WHERE $timeFilter - but that’s only for singlestat panel type - result is single number, this is not for time series panel.