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Update exponentialmovingaverage.md

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docs/en/sql-reference/aggregate-functions/reference/exponentialmovingaverage.md
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@ -11,15 +11,15 @@ sidebar_title: exponentialMovingAverage
**Syntax**
```sql
exponentialMovingAverage(x)(value, timestamp)
exponentialMovingAverage(x)(value, timeunit)
```
Each `value` corresponds to the determinate `timestamp`. The half-life `x` is the time lag at which the exponential weights decay by one-half. The function returns a weighted average: the older the time point, the less weight the corresponding value is considered to be.
Each `value` corresponds to the determinate `timeunit`. The half-life `x` is the time lag at which the exponential weights decay by one-half. The function returns a weighted average: the older the time point, the less weight the corresponding value is considered to be.
**Arguments**
- `value` — Value. [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md) or [Decimal](../../../sql-reference/data-types/decimal.md).
- `timestamp` — Timestamp. [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md) or [Decimal](../../../sql-reference/data-types/decimal.md).
- `timeunit` — Timeunit. [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md) or [Decimal](../../../sql-reference/data-types/decimal.md). Timeunit is not timestamp (seconds), it's -- an index of the time interval. Can be calculated using [intDiv](../../unctions/arithmetic-functions/#intdiva-b).
**Parameters**
@ -148,3 +148,33 @@ Result:
│ 1 │ 49 │ 0.825 │ █████████████████████████████████████████▎│
└───────┴──────┴──────────────────────┴────────────────────────────────────────────┘
```
```sql
CREATE TABLE data
ENGINE = Memory AS
SELECT
10 AS value,
toDateTime('2020-01-01') + (3600 * number) AS time
FROM numbers_mt(10);
SELECT
value,
time,
exponentialMovingAverage(1)(value, intDiv(toUInt32(time),3600)) OVER (ORDER BY time ASC) res
FROM data
ORDER BY time;
┌─value─┬────────────────time─┬─────────res─┐
│ 10 │ 2020-01-01 00:00:00 │ 5 │
│ 10 │ 2020-01-01 01:00:00 │ 7.5 │
│ 10 │ 2020-01-01 02:00:00 │ 8.75 │
│ 10 │ 2020-01-01 03:00:00 │ 9.375 │
│ 10 │ 2020-01-01 04:00:00 │ 9.6875 │
│ 10 │ 2020-01-01 05:00:00 │ 9.84375 │
│ 10 │ 2020-01-01 06:00:00 │ 9.921875 │
│ 10 │ 2020-01-01 07:00:00 │ 9.9609375 │
│ 10 │ 2020-01-01 08:00:00 │ 9.98046875 │
│ 10 │ 2020-01-01 09:00:00 │ 9.990234375 │
└───────┴─────────────────────┴─────────────┘
```