你当前正在访问 Microsoft Azure Global Edition 技术文档网站。 如果需要访问由世纪互联运营的 Microsoft Azure 中国技术文档网站，请访问 https://docs.azure.cn。
stdev() (aggregation function)
Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel
Calculates the standard deviation of expr across the group, using Bessel's correction for a small dataset that is considered a sample.
Null values are ignored and don't factor into the calculation.
For a large dataset that is representative of the population, use stdevp() (aggregation function).
Note
This function is used in conjunction with the summarize operator.
Formula
This function uses the following formula.
Syntax
stdev(expr)
Learn more about syntax conventions.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
| expr | string |
✔️ | The expression used for the standard deviation aggregation calculation. |
Returns
Returns the standard deviation value of expr across the group.
Example
The following example shows the standard deviation for the group.
range x from 1 to 5 step 1
| summarize make_list(x), stdev(x)
Output
| list_x | stdev_x |
|---|---|
| [ 1, 2, 3, 4, 5] | 1.58113883008419 |