Cross-Validation Resampling

Splits data using a folds-folds (default: 10 folds) cross-validation.

Dictionary

This Resampling can be instantiated via the dictionary mlr_resamplings or with the associated sugar function rsmp():

mlr_resamplings$get("cv")
rsmp("cv")

Parameters

• folds (integer(1))
  Number of folds.

References

Bischl B, Mersmann O, Trautmann H, Weihs C (2012). “Resampling Methods for Meta-Model Validation with Recommendations for Evolutionary Computation.” Evolutionary Computation, 20(2), 249--275. doi: 10.1162/evco_a_00069 .

See also

Dictionary of Resamplings: mlr_resamplings

as.data.table(mlr_resamplings) for a complete table of all (also dynamically created) Resampling implementations.

Other Resampling: Resampling, mlr_resamplings_bootstrap, mlr_resamplings_custom, mlr_resamplings_holdout, mlr_resamplings_insample, mlr_resamplings_loo, mlr_resamplings_repeated_cv, mlr_resamplings_subsampling, mlr_resamplings

Super class

mlr3::Resampling -> ResamplingCV

Active bindings

iters

(integer(1))
Returns the number of resampling iterations, depending on the values stored in the param_set.

Methods

Public methods

• ResamplingCV$new()

• ResamplingCV$clone()

Inherited methods

• mlr3::Resampling$format()

• mlr3::Resampling$help()

• mlr3::Resampling$instantiate()

• mlr3::Resampling$print()

• mlr3::Resampling$test_set()

• mlr3::Resampling$train_set()

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Method new()

Creates a new instance of this R6 class.

Usage

ResamplingCV$new()

---

Method clone()

The objects of this class are cloneable with this method.

Usage

ResamplingCV$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# Create a task with 10 observations
task = tsk("penguins")
task$filter(1:10)

# Instantiate Resampling
rcv = rsmp("cv", folds = 3)
rcv$instantiate(task)

# Individual sets:
rcv$train_set(1)
#> [1] 2 7 9 4 5 6
rcv$test_set(1)
#> [1]  1  3  8 10
intersect(rcv$train_set(1), rcv$test_set(1))
#> integer(0)

# Internal storage:
rcv$instance # table
#>     row_id fold
#>  1:      1    1
#>  2:      3    1
#>  3:      8    1
#>  4:     10    1
#>  5:      2    2
#>  6:      7    2
#>  7:      9    2
#>  8:      4    3
#>  9:      5    3
#> 10:      6    3