# varp


The `varp` function calculates the population variance of the set of numbers in the specified measure, grouped by the chosen dimension or dimensions.

## Syntax


```
varp(measure, [group-by level])
```

## Arguments


 *measure*   
The argument must be a measure. Null values are omitted from the results. Literal values don't work. The argument must be a field.

 *group-by level*   
(Optional) Specifies the level to group the aggregation by. The level added can be any dimension or dimensions independent of the dimensions added to the visual.  
The argument must be a dimension field. The group-by level must be enclosed in square brackets `[ ]`. For more information, see [Level-aware calculation - aggregate (LAC-A) functions](https://docs.amazonaws.cn/quicksight/latest/user/level-aware-calculations-aggregate.html).

## Examples


The following example returns the variance of a population of test scores.

```
varp({Scores})
```

You can also specify at what level to group the computation using one or more dimensions in the view or in your dataset. This is called a LAC-A function. For more information about LAC-A functions, see [Level-aware calculation - aggregate (LAC-A) functions](https://docs.amazonaws.cn/quicksight/latest/user/level-aware-calculations-aggregate.html). The following example returns the variance of a population test scores at the subject level, but not across other dimensions (Class) in the visual.

```
varp({Scores}, [Subject]
```