<!--
{
  "availability" : [
    "iOS: 15.0.0 - 16.0.0",
    "iPadOS: 15.0.0 - 16.0.0",
    "macCatalyst: 15.0.0 - 16.0.0",
    "macOS: 10.14.0 - 10.15.0",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CreateML",
  "identifier" : "/documentation/CreateML/MLDataColumn/std()",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Create ML",
      "CreateML"
    ],
    "preciseIdentifier" : "s:8CreateML12MLDataColumnVAASdRszrlE3stdSdSgyF::OverloadGroup"
  },
  "title" : "std()"
}
-->

# std()

Returns the standard deviation of the elements in a column of doubles.

```
func std() -> Double?
```

## Return Value

A <doc://com.apple.documentation/documentation/Swift/Double>; otherwise `nil` if the column is
invalid.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)