---
title: "train(trainingData:targetColumn:featureColumns:parameters:sessionParameters:)"
framework: createml
role: symbol
role_heading: Type Method
path: "createml/mlboostedtreeregressor/train(trainingdata:targetcolumn:featurecolumns:parameters:sessionparameters:)"
---

# train(trainingData:targetColumn:featureColumns:parameters:sessionParameters:)

Trains a boosted tree regressor.

## Declaration

```swift
static func train(trainingData: DataFrame, targetColumn: String, featureColumns: [String]? = nil, parameters: MLBoostedTreeRegressor.ModelParameters = ModelParameters(validation: .split(strategy: .automatic)), sessionParameters: MLTrainingSessionParameters = _defaultSessionParameters) throws -> MLJob<MLBoostedTreeRegressor>
```

## Parameters

- `trainingData`: A DataFrame specifying training data.
- `targetColumn`: A String specifying the target column name in the trainingData
- `featureColumns`: An optional list of Strings specifying feature columns to be used to predict the target, if not provided, default to use all the other columns in the trainingData, except the one specified by targetColumn
- `parameters`: Model training parameters. See doc://com.apple.createml/documentation/CreateML/MLBoostedTreeRegressor/ModelParameters-swift.struct for the defaults.
- `sessionParameters`: Training session parameters. See doc://com.apple.createml/documentation/CreateML/MLTrainingSessionParameters for the defaults.

## Return Value

Return Value A MLJob that can be used to observe training progress.

## Discussion

Discussion If sessionDirectory is provided it will save training progress. If there is progress already saved training will resume from the last checkpoint.

## See Also

### Training a boosted tree regressor asynchronously

- [makeTrainingSession(trainingData:targetColumn:featureColumns:parameters:sessionParameters:)](createml/mlboostedtreeregressor/maketrainingsession(trainingdata:targetcolumn:featurecolumns:parameters:sessionparameters:).md)
- [resume(_:)](createml/mlboostedtreeregressor/resume(_:).md)
- [restoreTrainingSession(sessionParameters:)](createml/mlboostedtreeregressor/restoretrainingsession(sessionparameters:).md)