stddev() function
The stddev()
function computes the standard deviation of non-null records in a specified column.
*Function type: Aggregate
**Output data type:* Float
stddev(
column: "_value",
mode: "sample"
)
Parameters
column
The column on which to operate. Defaults to "_value"
.
*Data type: String*
mode
The standard deviation mode or type of standard deviation to calculate. Defaults to "sample"
.
*Data type: String*
The available options are:
sample
Calculates the sample standard deviation where the data is considered to be part of a larger population.
population
Calculates the population standard deviation where the data is considered a population of its own.
Examples
from(bucket: "example-bucket")
|> range(start: -5m)
|> filter(fn: (r) =>
r._measurement == "cpu" and
r._field == "usage_system"
)
|> stddev()