Reference to the next() function

Summary

next([<timeWindow>,] <tsExpression>)

Fills in gaps in each time series described by tsExpression, by inserting data points that have the next known value of the time series. Specify timeWindow to fill in data for a limited period of time before each existing point.

Parameters

ParameterDescription
timeWindow Maximum amount of time to fill with inserted data points. If you omit this parameter, gaps of up to 4 weeks are completely filled.
You can specify a time measurement based on the clock or calendar (1s, 1m, 1h, 1d, 1w), the window length (1vw) of the chart, or the bucket size (1bw) of the chart. Default is minutes if the unit is not specified.
tsExpression Expression that describes the time series in which to replace data gaps with the next value.

Description

The next() function allows you to assign the next known reported data point value to a gap of missing data. If there’s a gap, nothing happens until the first new value becomes available. Then the data is backfilled with that, the next, value. No line (dotted or solid) is drawn until the next data point is reported.

By default, next() applies the next reported data value to gaps of missing data for up to 4 weeks. If you’d like this window to be smaller, you can use the timeWindow parameter.

Examples

In the following example, we’ve zoomed in on ~sample.cpu.loadavg.1m and see missing data.

ts_last before

We decide to replace the missing data with the last value before the gap, in this case 0.

ts_last

Then we replace the missing data with the first good value after the gap using next.

ts next

See Also

Using Moving and Tumbling Windows to Highlight trends

Other missing data functions include: