Create a graph with a calculation

I want to create a graph with the following calculation: x(n) = ax(n-1)+by(n)
{=exponential moving average}.
I have the data of y(n) and the constant a,b. Im working with influxdb.

Welcome to the forum.

You did not state if you are using InfluxQL or Flux, but there appears to be built-in support for Exponential Moving Average in both query methods…

I don’t find this function in my options in the query.
Do you know where it is located in the query?
Im working with InfluxQL.

Select moving_average and then change the view to the query builder by clicking the pencil icon…


and rewrite your query to include

EXPONENTIAL_MOVING_AVERAGE([ * | <field_key> | /regular_expression/ ], <period>[, <hold_period)[, <warmup_type]])

When I rewrite my query, its not saved and returns to last query, how can I save the changes?

Re-write your query in Raw mode as you wish, but do not then switch back to
the Query Editor. That’s all yu need to do. The query will remain as you
left it.