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# variance(), variance_y(), and variance_x() ToolkitTimescaleDB Toolkit functions are available under Timescale Community Edition. They are automatically included with Timescale Cloud. Click to learn more.

Toolkit

TimescaleDB Toolkit functions are available under Timescale Community Edition. They are automatically included with Timescale Cloud. Click to learn more.

`variance(summary StatsSummary1D, method TEXT) RETURNS BIGINT`

`variance_y(summary StatsSummary2D, method TEXT) RETURNS BIGINT`

`variance_x(summary StatsSummary2D, method TEXT) RETURNS BIGINT`

Get the variance of the values contained in a statistical aggregate.
In a two-dimensional `stats_agg`

use the `_y`

/ `_x`

form to access the
`variance`

of the dependent and independent variables.

The `method`

determines whether you calculate a population or sample variance.
These values can be provided as their full names, or you can abbreviate them to `pop`

or `samp`

. These are the only four accepted values for the `method`

argument. The
default is `sample`

.

For more information about statistical aggregate functions, see the hyperfunctions documentation.

## Required arguments

Name | Type | Description |
---|---|---|

`summary` | `StatsSummary1D` /`StatsSummary2D` | The already constructed data structure from a previous `stats_agg` call |

### Optional arguments

Name | Type | Description |
---|---|---|

`method` | `TEXT` | The method for the calculation 'population' or 'sample' (default) |

## Returns

Column | Type | Description |
---|---|---|

`variance` /`variance_y` /`variance_x` | `DOUBLE PRECISION` | The variance of the values in the statistical aggregate |

## Sample usage

```
SELECT variance_y(stats_agg(data, data))
FROM generate_series(0, 100) data;
```

```
variance_y
------------
858.5
```

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