Classification Logistic Regression Learner

Logistic regression with a quadratic penalization on the coefficient. Calls stepPlr::plr() from stepPlr.

Dictionary

This Learner can be instantiated via lrn():

lrn("classif.stepPlr")

Meta Information

• Task type: “classif”

• Predict Types: “response”, “prob”

• Feature Types: “logical”, “integer”, “numeric”

• Required Packages: mlr3, stepPlr

Parameters

Id	Type	Default	Levels	Range
cp	character	aic	aic, bic	-
lambda	numeric	1e-04		\([0, \infty)\)
offset.coefficients	untyped	-		-
offset.subset	untyped	-		-

References

Park, Young M, Hastie, Trevor (2007). “Penalized logistic regression for detecting gene interactions.” Biostatistics, 9(1), 30-50. ISSN 1465-4644, doi:10.1093/biostatistics/kxm010 , https://doi.org/10.1093/biostatistics/kxm010.

See also

• Dictionary of Learners: mlr3::mlr_learners.

• as.data.table(mlr_learners) for a table of available Learners in the running session (depending on the loaded packages).

• Chapter in the mlr3book: https://mlr3book.mlr-org.com/basics.html#learners

• mlr3learners for a selection of recommended learners.

• mlr3cluster for unsupervised clustering learners.

• mlr3pipelines to combine learners with pre- and postprocessing steps.

• mlr3tuning for tuning of hyperparameters, mlr3tuningspaces for established default tuning spaces.

Author

annanzrv

Super classes

mlr3::Learner -> mlr3::LearnerClassif -> LearnerClassifStepPlr

Methods

Public methods

• LearnerClassifStepPlr$new()

• LearnerClassifStepPlr$clone()

Inherited methods

• mlr3::Learner$base_learner()
• mlr3::Learner$configure()
• mlr3::Learner$encapsulate()
• mlr3::Learner$format()
• mlr3::Learner$help()
• mlr3::Learner$predict()
• mlr3::Learner$predict_newdata()
• mlr3::Learner$print()
• mlr3::Learner$reset()
• mlr3::Learner$selected_features()
• mlr3::Learner$train()
• mlr3::LearnerClassif$predict_newdata_fast()

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Method new()

Creates a new instance of this R6 class.

Usage

LearnerClassifStepPlr$new()

---

Method clone()

The objects of this class are cloneable with this method.

Usage

LearnerClassifStepPlr$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# Define the Learner
learner = lrn("classif.stepPlr")
print(learner)
#> 
#> ── <LearnerClassifStepPlr> (classif.stepPlr): Logistic Regression with a L2 Pena
#> • Model: -
#> • Parameters: list()
#> • Packages: mlr3 and stepPlr
#> • Predict Types: [response] and prob
#> • Feature Types: logical, integer, and numeric
#> • Encapsulation: none (fallback: -)
#> • Properties: twoclass and weights
#> • Other settings: use_weights = 'use'

# Define a Task
task = tsk("sonar")

# Create train and test set
ids = partition(task)

# Train the learner on the training ids
learner$train(task, row_ids = ids$train)

print(learner$model)
#> 
#> Call:
#> stepPlr::plr(x = data, y = y)
#> 
#> Coefficients:
#> Intercept        V1       V10       V11       V12       V13       V14       V15 
#>  12.99236  -5.24704  -4.58977 -26.37354 -39.11584  53.29766 -51.81838  18.66990 
#>       V16       V17       V18       V19        V2       V20       V21       V22 
#>  -0.56031  44.02693 -26.91266 -18.49256 -10.81871  18.59205   9.50198 -32.68360 
#>       V23       V24       V25       V26       V27       V28       V29        V3 
#>  17.78837 -24.73179  20.83514  11.30151 -21.44844  21.78554  -6.23622  49.40328 
#>       V30       V31       V32       V33       V34       V35       V36       V37 
#> -29.29573  55.86796 -32.41988  -0.15889   6.91038 -21.02687  36.22483  -6.09194 
#>       V38       V39        V4       V40       V41       V42       V43       V44 
#> -11.04253 -11.19409 -27.84835  45.39262  -3.86418 -26.17297   8.02486  -5.55456 
#>       V45       V46       V47       V48       V49        V5       V50       V51 
#>  -6.54033  13.96721 -39.99804 -18.90377 -46.41730   9.54932  -5.79837 -55.59493 
#>       V52       V53       V54       V55       V56       V57       V58       V59 
#> -46.06666 -29.36224 -25.01759  10.78841   4.37226   7.70260 -24.52563 -34.03616 
#>        V6       V60        V7        V8        V9 
#> -17.96721 -20.21074  40.52500   0.23911 -16.78166 
#> 
#>     Null deviance: 191.07 on 138 degrees of freedom
#> Residual deviance: 7.9 on 96.41 degrees of freedom
#>             Score: deviance + 4.9 * df = 218.08 


# Make predictions for the test rows
predictions = learner$predict(task, row_ids = ids$test)

# Score the predictions
predictions$score()
#> classif.ce 
#>  0.3478261