# ml_linear_regression

Spark ML – Linear Regression

## Description

Perform regression using linear regression.

## Usage

```
ml_linear_regression(
x,formula = NULL,
fit_intercept = TRUE,
elastic_net_param = 0,
reg_param = 0,
max_iter = 100,
weight_col = NULL,
loss = "squaredError",
solver = "auto",
standardization = TRUE,
tol = 1e-06,
features_col = "features",
label_col = "label",
prediction_col = "prediction",
uid = random_string("linear_regression_"),
... )
```

## Arguments

Argument | Description |
---|---|

x | A `spark_connection` , `ml_pipeline` , or a `tbl_spark` . |

formula | Used when `x` is a `tbl_spark` . R formula as a character string or a formula. This is used to transform the input dataframe before fitting, see ft_r_formula for details. |

fit_intercept | Boolean; should the model be fit with an intercept term? |

elastic_net_param | ElasticNet mixing parameter, in range [0, 1]. For alpha = 0, the penalty is an L2 penalty. For alpha = 1, it is an L1 penalty. |

reg_param | Regularization parameter (aka lambda) |

max_iter | The maximum number of iterations to use. |

weight_col | The name of the column to use as weights for the model fit. |

loss | The loss function to be optimized. Supported options: “squaredError” and “huber”. Default: “squaredError” |

solver | Solver algorithm for optimization. |

standardization | Whether to standardize the training features before fitting the model. |

tol | Param for the convergence tolerance for iterative algorithms. |

features_col | Features column name, as a length-one character vector. The column should be single vector column of numeric values. Usually this column is output by `ft_r_formula` . |

label_col | Label column name. The column should be a numeric column. Usually this column is output by `ft_r_formula` . |

prediction_col | Prediction column name. |

uid | A character string used to uniquely identify the ML estimator. |

… | Optional arguments; see Details. |

## Details

When `x`

is a `tbl_spark`

and `formula`

(alternatively, `response`

and `features`

) is specified, the function returns a `ml_model`

object wrapping a `ml_pipeline_model`

which contains data pre-processing transformers, the ML predictor, and, for classification models, a post-processing transformer that converts predictions into class labels. For classification, an optional argument `predicted_label_col`

(defaults to `"predicted_label"`

) can be used to specify the name of the predicted label column. In addition to the fitted `ml_pipeline_model`

, `ml_model`

objects also contain a `ml_pipeline`

object where the ML predictor stage is an estimator ready to be fit against data. This is utilized by `ml_save`

with `type = "pipeline"`

to faciliate model refresh workflows.

## Value

The object returned depends on the class of `x`

.

`spark_connection`

: When`x`

is a`spark_connection`

, the function returns an instance of a`ml_estimator`

object. The object contains a pointer to a Spark`Predictor`

object and can be used to compose`Pipeline`

objects.`ml_pipeline`

: When`x`

is a`ml_pipeline`

, the function returns a`ml_pipeline`

with the predictor appended to the pipeline.`tbl_spark`

: When`x`

is a`tbl_spark`

, a predictor is constructed then immediately fit with the input`tbl_spark`

, returning a prediction model.`tbl_spark`

, with`formula`

: specified When`formula`

is specified, the input`tbl_spark`

is first transformed using a`RFormula`

transformer before being fit by the predictor. The object returned in this case is a`ml_model`

which is a wrapper of a`ml_pipeline_model`

.

## Examples

```
<- spark_connect(master = "local")
sc <- sdf_copy_to(sc, mtcars, name = "mtcars_tbl", overwrite = TRUE)
mtcars_tbl
<- mtcars_tbl %>%
partitions sdf_random_split(training = 0.7, test = 0.3, seed = 1111)
<- partitions$training
mtcars_training <- partitions$test
mtcars_test
<- mtcars_training %>%
lm_model ml_linear_regression(mpg ~ .)
<- ml_predict(lm_model, mtcars_test)
pred
ml_regression_evaluator(pred, label_col = "mpg")
```

## See Also

See https://spark.apache.org/docs/latest/ml-classification-regression.html for more information on the set of supervised learning algorithms.

Other ml algorithms: `ml_aft_survival_regression()`

, `ml_decision_tree_classifier()`

, `ml_gbt_classifier()`

, `ml_generalized_linear_regression()`

, `ml_isotonic_regression()`

, `ml_linear_svc()`

, `ml_logistic_regression()`

, `ml_multilayer_perceptron_classifier()`

, `ml_naive_bayes()`

, `ml_one_vs_rest()`

, `ml_random_forest_classifier()`