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53 lines
1.1 KiB
Markdown
53 lines
1.1 KiB
Markdown
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---
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title: "varPopStable"
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slug: "/ja/sql-reference/aggregate-functions/reference/varpopstable"
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sidebar_position: 211
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---
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## varPopStable
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母集団分散を返します。[`varPop`](../reference/varpop.md)とは異なり、この関数は[数値的に安定した](https://en.wikipedia.org/wiki/Numerical_stability)アルゴリズムを使用します。動作は遅いですが、計算誤差が少ないです。
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**構文**
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```sql
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varPopStable(x)
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```
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エイリアス: `VAR_POP_STABLE`.
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**パラメータ**
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- `x`: 母集団分散を求める値の集まり。[(U)Int*](../../data-types/int-uint.md), [Float*](../../data-types/float.md), [Decimal*](../../data-types/decimal.md).
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**返される値**
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- `x`の母集団分散を返します。[Float64](../../data-types/float.md).
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**例**
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クエリ:
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```sql
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DROP TABLE IF EXISTS test_data;
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CREATE TABLE test_data
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(
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x UInt8,
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)
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ENGINE = Memory;
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INSERT INTO test_data VALUES (3),(3),(3),(4),(4),(5),(5),(7),(11),(15);
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SELECT
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varPopStable(x) AS var_pop_stable
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FROM test_data;
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```
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結果:
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```response
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┌─var_pop_stable─┐
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│ 14.4 │
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└────────────────┘
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```
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