logistic_reg: Logistic regression

In parsnip: A Common API to Modeling and Analysis Functions

Logistic regression

Description

logistic_reg() defines a generalized linear model for binary outcomes. A linear combination of the predictors is used to model the log odds of an event. This function can fit classification models.

\Sexpr[stage=render,results=rd]{parsnip:::make_engine_list("logistic_reg")}

More information on how parsnip is used for modeling is at https://www.tidymodels.org/.

Usage

logistic_reg(
  mode = "classification",
  engine = "glm",
  penalty = NULL,
  mixture = NULL
)

Arguments

mode	A single character string for the type of model. The only possible value for this model is "classification".
engine	A single character string specifying what computational engine to use for fitting. Possible engines are listed below. The default for this model is "glm".
penalty	A non-negative number representing the total amount of regularization (specific engines only). For keras models, this corresponds to purely L2 regularization (aka weight decay) while the other models can be either or a combination of L1 and L2 (depending on the value of mixture).
mixture	A number between zero and one (inclusive) giving the proportion of L1 regularization (i.e. lasso) in the model. mixture = 1 specifies a pure lasso model, mixture = 0 specifies a ridge regression model, and ⁠0 < mixture < 1⁠ specifies an elastic net model, interpolating lasso and ridge. Available for specific engines only. For LiblineaR models, mixture must be exactly 1 or 0 only.

Details

This function only defines what type of model is being fit. Once an engine is specified, the method to fit the model is also defined. See set_engine() for more on setting the engine, including how to set engine arguments.

The model is not trained or fit until the fit() function is used with the data.

Each of the arguments in this function other than mode and engine are captured as quosures. To pass values programmatically, use the injection operator like so:

value <- 1
logistic_reg(argument = !!value)

This model fits a classification model for binary outcomes; for multiclass outcomes, see multinom_reg().

References

https://www.tidymodels.org, Tidy Modeling with R, searchable table of parsnip models

See Also

\Sexpr[stage=render,results=rd]{parsnip:::make_seealso_list("logistic_reg")}

Examples

show_engines("logistic_reg")

logistic_reg()

parsnip documentation built on Aug. 18, 2023, 1:07 a.m.