102 lines
2.8 KiB
Markdown
102 lines
2.8 KiB
Markdown
|
|
Use [`movingAverage()`](/flux/v0/stdlib/universe/movingaverage/)
|
|
or [`timedMovingAverage()`](/flux/v0/stdlib/universe/timedmovingaverage/)
|
|
to return the moving average of data.
|
|
|
|
```js
|
|
data
|
|
|> movingAverage(n: 5)
|
|
|
|
// OR
|
|
|
|
data
|
|
|> 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 |
|
|
|:-----:|:----------- |
|
|
| 1 | _Insufficient number of rows_ |
|
|
| 2 | _Insufficient number of rows_ |
|
|
| 3 | (Row1 + Row2 + Row3) / 3 |
|
|
| 4 | (Row2 + Row3 + Row4) / 3 |
|
|
| 5 | (Row3 + Row4 + Row5) / 3 |
|
|
|
|
{{< flex >}}
|
|
{{% flex-content %}}
|
|
**Given the following input:**
|
|
|
|
| _time | _value |
|
|
|:----- | ------:|
|
|
| 2020-01-01T00:01:00Z | 1.0 |
|
|
| 2020-01-01T00:02:00Z | 1.2 |
|
|
| 2020-01-01T00:03:00Z | 1.8 |
|
|
| 2020-01-01T00:04:00Z | 0.9 |
|
|
| 2020-01-01T00:05:00Z | 1.4 |
|
|
| 2020-01-01T00:06:00Z | 2.0 |
|
|
{{% /flex-content %}}
|
|
{{% flex-content %}}
|
|
**The following would return:**
|
|
|
|
```js
|
|
|> movingAverage(n: 3)
|
|
```
|
|
|
|
| _time | _value |
|
|
|:----- | ------:|
|
|
| 2020-01-01T00:03:00Z | 1.33 |
|
|
| 2020-01-01T00:04:00Z | 1.30 |
|
|
| 2020-01-01T00:05:00Z | 1.36 |
|
|
| 2020-01-01T00:06:00Z | 1.43 |
|
|
{{% /flex-content %}}
|
|
{{< /flex >}}
|
|
|
|
### 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`:
|
|
|
|
{{< svg "/static/svgs/timed-moving-avg.svg" >}}
|
|
|
|
{{< flex >}}
|
|
{{% flex-content %}}
|
|
**Given the following input:**
|
|
|
|
| _time | _value |
|
|
|:----- | ------:|
|
|
| 2020-01-01T00:00:00Z | 1.0 |
|
|
| 2020-01-01T00:30:00Z | 1.2 |
|
|
| 2020-01-01T01:00:00Z | 1.8 |
|
|
| 2020-01-01T01:30:00Z | 0.9 |
|
|
| 2020-01-01T02:00:00Z | 1.4 |
|
|
| 2020-01-01T02:30:00Z | 2.0 |
|
|
| 2020-01-01T03:00:00Z | 1.9 |
|
|
{{% /flex-content %}}
|
|
{{% flex-content %}}
|
|
**The following would return:**
|
|
|
|
```js
|
|
|> timedMovingAverage(every: 30m, period: 1h)
|
|
```
|
|
|
|
| _time | _value |
|
|
| :------------------- | -----: |
|
|
| 2020-01-01T00:30:00Z | 1.0 |
|
|
| 2020-01-01T01:00:00Z | 1.1 |
|
|
| 2020-01-01T01:30:00Z | 1.5 |
|
|
| 2020-01-01T02:00:00Z | 1.35 |
|
|
| 2020-01-01T02:30:00Z | 1.15 |
|
|
| 2020-01-01T03:00:00Z | 1.7 |
|
|
| 2020-01-01T03:00:00Z | 2 |
|
|
{{% /flex-content %}}
|
|
{{< /flex >}}
|