mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-27 10:02:01 +00:00
15 lines
592 B
Markdown
15 lines
592 B
Markdown
|
---
|
||
|
toc_priority: 33
|
||
|
---
|
||
|
|
||
|
# varSamp {#varsamp}
|
||
|
|
||
|
Calculates the amount `Σ((x - x̅)^2) / (n - 1)`, where `n` is the sample size and `x̅`is the average value of `x`.
|
||
|
|
||
|
It represents an unbiased estimate of the variance of a random variable if passed values form its sample.
|
||
|
|
||
|
Returns `Float64`. When `n <= 1`, returns `+∞`.
|
||
|
|
||
|
!!! 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 `varSampStable` function. It works slower but provides a lower computational error.
|