content/flux/v0/stdlib/universe/truncatetimecolumn.md
truncateTimeColumn() truncates all input time values in the _time to a
specified unit.
When truncating a time value to the week (1w), weeks are determined using the
Unix epoch (1970-01-01T00:00:00Z UTC). The Unix epoch was on a Thursday,
so all calculated weeks begin on Thursday.
(<-tables: stream[{B with _time: C}], unit: duration, ?timeColumn: A) => stream[{B with _time: C, _time: time}] where C: Timeable
{{% caption %}} For more information, see Function type signatures. {{% /caption %}}
({{< req >}}) Unit of time to truncate to.
Example units:
Time column to truncate. Default is _time.
Note: Currently, assigning a custom value to this parameter will have no effect.
Input data. Default is piped-forward data (<-).
import "sampledata"
sampledata.int()
|> truncateTimeColumn(unit: 1m)
{{< expand-wrapper >}} {{% expand "View example input and output" %}}
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | -2 | t1 |
| 2021-01-01T00:00:10Z | 10 | t1 |
| 2021-01-01T00:00:20Z | 7 | t1 |
| 2021-01-01T00:00:30Z | 17 | t1 |
| 2021-01-01T00:00:40Z | 15 | t1 |
| 2021-01-01T00:00:50Z | 4 | t1 |
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | 19 | t2 |
| 2021-01-01T00:00:10Z | 4 | t2 |
| 2021-01-01T00:00:20Z | -3 | t2 |
| 2021-01-01T00:00:30Z | 19 | t2 |
| 2021-01-01T00:00:40Z | 13 | t2 |
| 2021-01-01T00:00:50Z | 1 | t2 |
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | -2 | t1 |
| 2021-01-01T00:00:00Z | 10 | t1 |
| 2021-01-01T00:00:00Z | 7 | t1 |
| 2021-01-01T00:00:00Z | 17 | t1 |
| 2021-01-01T00:00:00Z | 15 | t1 |
| 2021-01-01T00:00:00Z | 4 | t1 |
| _time | _value | *tag |
|---|---|---|
| 2021-01-01T00:00:00Z | 19 | t2 |
| 2021-01-01T00:00:00Z | 4 | t2 |
| 2021-01-01T00:00:00Z | -3 | t2 |
| 2021-01-01T00:00:00Z | 19 | t2 |
| 2021-01-01T00:00:00Z | 13 | t2 |
| 2021-01-01T00:00:00Z | 1 | t2 |
{{% /expand %}} {{< /expand-wrapper >}}