Calculates the standard deviation for a field over a set of events. The result is returned in a field named _stddev

Function Traits: Aggregate

ParameterTypeRequiredDefaultDescription
asstringoptional_stddev Name of output field.
field[a]stringrequired  Field to extract a number from and calculate standard deviation over.

[a] The argument name field can be omitted.

The parameter name for field can be omitted; the following forms are equivalent:

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stdDev("value")

and:

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stdDev(field="value")

stdDev() Examples

Find the standard deviation of bytes send in http responses

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stdDevBytes := stdDev(field=bytes_sent)