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17 lines
643 B
Markdown
17 lines
643 B
Markdown
---
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slug: /en/sql-reference/aggregate-functions/reference/varsamp
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sidebar_position: 33
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---
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# varSamp
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Calculates the amount `Σ((x - x̅)^2) / (n - 1)`, where `n` is the sample size and `x̅`is the average value of `x`.
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It represents an unbiased estimate of the variance of a random variable if passed values from its sample.
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Returns `Float64`. When `n <= 1`, returns `+∞`.
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:::note
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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.
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:::
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