`brulee::brulee_linear_reg()`

uses ordinary least squares to fit models with
numeric outcomes.

## Details

For this engine, there is a single mode: regression

### Tuning Parameters

This model has 2 tuning parameter:

`penalty`

: Amount of Regularization (type: double, default: 0.001)`mixture`

: Proportion of Lasso Penalty (type: double, default: 0.0)

The use of the L1 penalty (a.k.a. the lasso penalty) does *not* force
parameters to be strictly zero (as it does in packages such as glmnet).
The zeroing out of parameters is a specific feature the optimization
method used in those packages.

Other engine arguments of interest:

`optimizer()`

: The optimization method. See`brulee::brulee_linear_reg()`

.`epochs()`

: An integer for the number of passes through the training set.`lean_rate()`

: A number used to accelerate the gradient decsent process.`momentum()`

: A number used to use historical gradient infomration during optimization (`optimizer = "SGD"`

only).`batch_size()`

: An integer for the number of training set points in each batch.`stop_iter()`

: A non-negative integer for how many iterations with no improvement before stopping. (default: 5L).

### Translation from parsnip to the original package (regression)

```
linear_reg(penalty = double(1)) %>%
set_engine("brulee") %>%
translate()
```

### Preprocessing requirements

Factor/categorical predictors need to be converted to numeric values
(e.g., dummy or indicator variables) for this engine. When using the
formula method via `fit()`

, parsnip will
convert factor columns to indicators.

Predictors should have the same scale. One way to achieve this is to center and scale each so that each predictor has mean zero and a variance of one.