Calculate the moving average

Use the movingAverage() or timedMovingAverage() functions to return the moving average of data.

  1. data
  2. |> movingAverage(n: 5)
  3. // OR
  4. data
  5. |> timedMovingAverage(every: 5m, period: 10m)

movingAverage()

For each row in a table, movingAverage() returns the average of the current value and previous values where n is the total number of values used to calculate the average.

If n = 3:

Row #Calculation
1Insufficient number of rows
2Insufficient number of rows
3(Row1 + Row2 + Row3) / 3
4(Row2 + Row3 + Row4) / 3
5(Row3 + Row4 + Row5) / 3

Given the following input:

_time_value
2020-01-01T00:01:00Z1.0
2020-01-01T00:02:00Z1.2
2020-01-01T00:03:00Z1.8
2020-01-01T00:04:00Z0.9
2020-01-01T00:05:00Z1.4
2020-01-01T00:06:00Z2.0

The following would return:

  1. |> movingAverage(n: 3)
_time_value
2020-01-01T00:03:00Z1.33
2020-01-01T00:04:00Z1.30
2020-01-01T00:05:00Z1.36
2020-01-01T00:06:00Z1.43

timedMovingAverage()

For each row in a table, timedMovingAverage() returns the average of the current value and all row values in the previous period (duration). It returns moving averages at a frequency defined by the every parameter.

Each color in the diagram below represents a period of time used to calculate an average and the time a point representing the average is returned. If every = 30m and period = 1h:

Moving Average - 图1

Given the following input:

_time_value
2020-01-01T00:01:00Z1.0
2020-01-01T00:02:00Z1.2
2020-01-01T00:03:00Z1.8
2020-01-01T00:04:00Z0.9
2020-01-01T00:05:00Z1.4
2020-01-01T00:06:00Z2.0

The following would return:

  1. |> timedMovingAverage(
  2. every: 2m,
  3. period: 4m
  4. )
_time_value
2020-01-01T00:02:00Z1.000
2020-01-01T00:04:00Z1.333
2020-01-01T00:06:00Z1.325
2020-01-01T00:06:00Z1.150

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query moving average