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85 lines
1.5 KiB
Markdown
85 lines
1.5 KiB
Markdown
---
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toc_priority: 107
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---
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# avgWeighted {#avgweighted}
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计算 [加权算术平均值](https://en.wikipedia.org/wiki/Weighted_arithmetic_mean)。
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**语法**
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``` sql
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avgWeighted(x, weight)
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```
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**参数**
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- `x` — 值。
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- `weight` — 值的加权。
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`x` 和 `weight` 的类型必须是
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[整数](../../../sql-reference/data-types/int-uint.md), 或
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[浮点数](../../../sql-reference/data-types/float.md), 或
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[定点数](../../../sql-reference/data-types/decimal.md),
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但是可以不一样。
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**返回值**
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- `NaN`。 如果所有的权重都等于0 或所提供的权重参数是空。
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- 加权平均值。 其他。
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类型: 总是[Float64](../../../sql-reference/data-types/float.md).
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**示例**
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查询:
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``` sql
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SELECT avgWeighted(x, w)
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FROM values('x Int8, w Int8', (4, 1), (1, 0), (10, 2))
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```
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结果:
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``` text
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┌─avgWeighted(x, weight)─┐
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│ 8 │
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└────────────────────────┘
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```
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**示例**
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查询:
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``` sql
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SELECT avgWeighted(x, w)
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FROM values('x Int8, w Int8', (0, 0), (1, 0), (10, 0))
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```
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结果:
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``` text
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┌─avgWeighted(x, weight)─┐
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│ nan │
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└────────────────────────┘
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```
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**示例**
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查询:
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``` sql
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CREATE table test (t UInt8) ENGINE = Memory;
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SELECT avgWeighted(t) FROM test
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```
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结果:
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``` text
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┌─avgWeighted(x, weight)─┐
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│ nan │
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└────────────────────────┘
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```
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