ClickHouse/docs/en/sql-reference/aggregate-functions/reference/covarpop.md

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toc_priority: 36
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# covarPop {#covarpop}

Syntax: `covarPop(x, y)`

Calculates the value of `Σ((x - x̅)(y - y̅)) / n`.

!!! note "Note"
    This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the `covarPopStable` function. It works slower but provides a lower computational error.
[docs] split aggregate function and system table references (#11742) * prefer relative links from root * wip * split aggregate function reference * split system tables 2020-06-18 08:24:31 +00:00			`---`
Revert "Format changes for new docs" 2022-04-03 23:05:35 +00:00			`toc_priority: 36`
[docs] split aggregate function and system table references (#11742) * prefer relative links from root * wip * split aggregate function reference * split system tables 2020-06-18 08:24:31 +00:00			`---`

			`# covarPop {#covarpop}`

			Syntax: `covarPop(x, y)`

			Calculates the value of `Σ((x - x̅)(y - y̅)) / n`.

Revert "Format changes for new docs" 2022-04-03 23:05:35 +00:00			`!!! note "Note"`
			This function uses a numerically unstable algorithm. If you need [numerical stability](https://en.wikipedia.org/wiki/Numerical_stability) in calculations, use the `covarPopStable` function. It works slower but provides a lower computational error.