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# MetricsKey

A key that uniquely identifies a metric.

```
struct MetricsKey
```

## Topics

### Getting the properties

[`static let source: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/source)

A key associated with a temporal stream source (e.g. a file name).

[`static let trainingAccuracy: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/trainingAccuracy)

A key associated with a training accuracy metric.

[`static let trainingError: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/trainingError)

A key associated with a training error metric.

[`static let trainingLoss: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/trainingLoss)

A key associated with a training loss metric.

[`static let trainingMaximumError: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/trainingMaximumError)

A key associated with a training maximum error metric.

[`static let trainingMeanAveragePrecision: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/trainingMeanAveragePrecision)

A key associated with a training mean average precision metric.

[`static let validationAccuracy: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/validationAccuracy)

A key associated with a validation accuracy metric.

[`static let validationError: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/validationError)

A key associated with a validation error metric.

[`static let validationLoss: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/validationLoss)

A key associated with a validation loss metric.

[`static let validationMaximumError: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/validationMaximumError)

A key associated with a validation maximum error metric.

[`static let validationMeanAveragePrecision: MetricsKey`](/documentation/CreateMLComponents/MetricsKey/validationMeanAveragePrecision)

A key associated with a validation mean average precision metric.

## Relationships

### Conforms To

[`Escapable`](/documentation/Swift/Escapable)

[`Copyable`](/documentation/Swift/Copyable)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`Sendable`](/documentation/Swift/Sendable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

[`Hashable`](/documentation/Swift/Hashable)

[`Equatable`](/documentation/Swift/Equatable)

---

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