---
title: MLRegressorMetrics
framework: createml
role: symbol
role_heading: Structure
path: createml/mlregressormetrics
---

# MLRegressorMetrics

Metrics you use to evaluate a regressor’s performance.

## Declaration

```swift
struct MLRegressorMetrics
```

## Mentioned in

Improving Your Model’s Accuracy

## Overview

Overview To understand what performance you can expect from the regressor, you start by looking at its maximumError. This high-level metric indicates your model’s worst-case performance. To get a sense for how your model performs on average, look at the rootMeanSquaredError. In both cases, you want to minimize the value and therefore the error. note: Each trained model contains different metrics for its various data sets (training, validation, and testing). Improving Your Model’s Accuracy compares these metrics among different data sets.

## Topics

### Understanding the model

- [maximumError](createml/mlregressormetrics/maximumerror.md)
- [rootMeanSquaredError](createml/mlregressormetrics/rootmeansquarederror.md)

### Handling errors

- [isValid](createml/mlregressormetrics/isvalid.md)
- [error](createml/mlregressormetrics/error.md)

### Creating metrics

- [init(maximumError:rootMeanSquaredError:)](createml/mlregressormetrics/init(maximumerror:rootmeansquarederror:).md)

### Describing metrics

- [description](createml/mlregressormetrics/description.md)
- [debugDescription](createml/mlregressormetrics/debugdescription.md)
- [playgroundDescription](createml/mlregressormetrics/playgrounddescription.md)

### Default Implementations

- [CustomDebugStringConvertible Implementations](createml/mlregressormetrics/customdebugstringconvertible-implementations.md)
- [CustomPlaygroundDisplayConvertible Implementations](createml/mlregressormetrics/customplaygrounddisplayconvertible-implementations.md)
- [CustomStringConvertible Implementations](createml/mlregressormetrics/customstringconvertible-implementations.md)

## Relationships

### Conforms To

- [Copyable](swift/copyable.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomPlaygroundDisplayConvertible](swift/customplaygrounddisplayconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Escapable](swift/escapable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)

## See Also

### Model accuracy

- [Improving Your Model’s Accuracy](createml/improving-your-model-s-accuracy.md)
- [MLClassifierMetrics](createml/mlclassifiermetrics.md)
- [MLWordTaggerMetrics](createml/mlwordtaggermetrics.md)
- [MLRecommenderMetrics](createml/mlrecommendermetrics.md)
- [MLObjectDetectorMetrics](createml/mlobjectdetectormetrics.md)