# integrate(set[])¶

Given an arbitrary number of series, performs a *numerical integration*
on each series to return a set of equal length. This is equivalent to
computing the *cumulative sum* over the series, where each point in the
returned series is the sum of the current point and the accumulated sum
of all previous points in the series.

**Example:**

The following expression plots the sum of `AWS.EC2.CPUCreditUsage`

and all previous values of `AWS.EC2.CPUCreditUsage`

which display in a given time period.
The series in the example includes the optional fields `period`

and `function`

, which if removed will default to the metric’s native period and a summary statistic of mean.

```
integrate(sum(s("AWS.EC2.CPUCreditUsage", "*", { period:"60", function:"sum" })))
```

The chart below demonstrates how the integration expression (provided above) starts at the actual value of the metric and continuously climbs at the rate of the next metric value provided.

Comparing the rising metric value minute over minute you will see the composite metric increase from `76.66`

to `91.74`

. This is an increase of `15.08`

, the value of `AWS.EC2.CPUCreditUsage`

.