# Metrics Operators

This guide describes Sumo Logic metrics operators and provides usage examples.

## Guide contents

In this section, we'll introduce the following concepts:

#### accum

Learn how to create a series of running totals for each metric time series.

#### along

Learn how to control what results are joined based on the value of one or more result fields.

#### avg

Learn how to calculate the average of all matching time series.

#### bottomk

Learn how to apply a specified aggregation function to the time series that match the query selector.

#### count

Learn how to count the total number of time series that match the query.

#### delta

Learn how to compute the backward difference at each data point in the time series.

#### eval

Learn how to evaluate a time series based on a user-specified arithmetic or mathematical function.

#### ewma

Learn how to compute an EWMA on the data points returned by the query for the selected time range.

#### fillmissing

Learn how to fill empty time slices in metric query results with a derived data point.

#### filter

Learn how to limit the results returned by a metric query.

#### histogram_quantile

Learn how to calculate the φ-quantile from the buckets of a histogram.

#### in

Learn how to use this operator in a metrics query selector as shorthand for multiple OR conditions.

#### max

Learn how to calculate the maximum value of the time series that match the query.

#### min

Learn how to calculate the minimum value of the time series that match the query.

#### outlier

Learn how to identify metrics data points that are outside the range of expected values.

#### parse

Learn how to parse the specified field to create new fields to use in the metrics query.

#### predict

Learn how to take a single time series metric to predict future values.

#### pct

Learn how to calculate the nth percentile of values of the input series for each time interval.

#### quantize

Learn how to use this operator to control Sumo’s quantization behavior.

#### rate

Learn how to calculate the per-second rate of change between consecutive data points.

#### stddev

Learn how to measure the magnitude of deviations between the values in a time series.

#### sum

Learn how to calculate the sum of the metrics values that match the query.

#### timeshift

Learn how to shift the time series from your metrics query by a specified period of time.

#### topk

Learn to apply a specified aggregation function to the time series that match the query selector.

#### where

Learn how to filter out entire time series, or individual data points within a time series.