LESSClassifier {less}

LESSClassifier

Description

Classifier for Learning with Subset Stacking (LESS)

Value

R6 class of LESSClassifier

Super classes

less::BaseEstimator -> less::SklearnEstimator -> less::LESSBase -> LESSClassifier

Methods

Public methods

• LESSClassifier$new()

• LESSClassifier$fit()

• LESSClassifier$predict()

• LESSClassifier$get_estimator_type()

• LESSClassifier$set_random_state()

• LESSClassifier$clone()

Inherited methods

• less::BaseEstimator$get_all_fields()
• less::BaseEstimator$get_attributes()
• less::SklearnEstimator$get_type()
• less::LESSBase$get_d_normalize()
• less::LESSBase$get_frac()
• less::LESSBase$get_isFitted()
• less::LESSBase$get_n_neighbors()
• less::LESSBase$get_n_replications()
• less::LESSBase$get_n_subsets()
• less::LESSBase$get_random_state()
• less::LESSBase$get_replications()
• less::LESSBase$get_scaling()
• less::LESSBase$get_val_size()

Method new()

Creates a new instance of R6 Class of LESSClassifier

Usage

LESSClassifier$new(
  frac = NULL,
  n_neighbors = NULL,
  n_subsets = NULL,
  n_replications = 20,
  d_normalize = TRUE,
  val_size = NULL,
  random_state = NULL,
  tree_method = function(X) KDTree$new(X),
  cluster_method = NULL,
  local_estimator = LinearRegression$new(),
  global_estimator = DecisionTreeClassifier$new(),
  distance_function = NULL,
  scaling = TRUE,
  warnings = TRUE,
  multiclass = "ovr"
)

Arguments

frac

fraction of total samples used for the number of neighbors (default is 0.05)

n_neighbors

number of neighbors (default is NULL)

n_subsets

number of subsets (default is NULL)

n_replications

number of replications (default is 20)

d_normalize

distance normalization (default is TRUE)

val_size

percentage of samples used for validation (default is NULL - no validation)

random_state

initialization of the random seed (default is NULL)

tree_method

method used for constructing the nearest neighbor tree, e.g., less::KDTree (default)

cluster_method

method used for clustering the subsets, e.g., less::KMeans (default is NULL)

local_estimator

estimator for the local models (default is less::LinearRegression)

global_estimator

estimator for the global model (default is less::DecisionTreeRegressor)

distance_function

distance function evaluating the distance from a subset to a sample, e.g., df(subset, sample) which returns a vector of distances (default is RBF(subset, sample, 1.0/n_subsets^2))

scaling

flag to normalize the input data (default is TRUE)

warnings

flag to turn on (TRUE) or off (FALSE) the warnings (default is TRUE)

multiclass

available strategies are 'ovr' (one-vs-rest, default), 'ovo' (one-vs-one), 'occ' (output-code-classifier) (default is 'ovr')

Examples

lessclassifier <- LESSClassifier$new()
lessclassifier <- LESSClassifier$new(multiclass = "ovo")

Method fit()

Dummy fit function that calls the fit method of the multiclass strategy

Usage

LESSClassifier$fit(X, y)

Arguments

X

2D matrix or dataframe that includes predictors

y

1D vector or (n,1) dimensional matrix/dataframe that includes response variables

Returns

Fitted R6 Class of LESSClassifier

Examples

data(iris)
set.seed(2022)
shuffled_iris <- iris[sample(1:nrow(iris)),]
split_list <- train_test_split(shuffled_iris[1:10,], test_size =  0.3, random_state = 1)
X_train <- split_list[[1]]
X_test <- split_list[[2]]
y_train <- split_list[[3]]
y_test <- split_list[[4]]

lessclassifier <- LESSClassifier$new()
lessclassifier$fit(X_train, y_train)

Method predict()

Dummy predict function that calls the predict method of the multiclass strategy

Usage

LESSClassifier$predict(X0)

Arguments

X0

2D matrix or dataframe that includes predictors

Returns

Predicted values of the given predictors

Examples

preds <- lessclassifier$predict(X_test)
print(caret::confusionMatrix(data=factor(preds), reference = factor(y_test)))

Method get_estimator_type()

Auxiliary function returning the estimator type e.g 'regressor', 'classifier'

Usage

LESSClassifier$get_estimator_type()

Examples

lessclassifier$get_estimator_type()

Method set_random_state()

Auxiliary function that sets random state attribute of the self class

Usage

LESSClassifier$set_random_state(random_state)

Arguments

random_state

seed number to be set as random state

Returns

self

Examples

lessclassifier$set_random_state(2022)

Method clone()

The objects of this class are cloneable with this method.

Usage

LESSClassifier$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

## ------------------------------------------------
## Method `LESSClassifier$new`
## ------------------------------------------------

lessclassifier <- LESSClassifier$new()
lessclassifier <- LESSClassifier$new(multiclass = "ovo")

## ------------------------------------------------
## Method `LESSClassifier$fit`
## ------------------------------------------------

data(iris)
set.seed(2022)
shuffled_iris <- iris[sample(1:nrow(iris)),]
split_list <- train_test_split(shuffled_iris[1:10,], test_size =  0.3, random_state = 1)
X_train <- split_list[[1]]
X_test <- split_list[[2]]
y_train <- split_list[[3]]
y_test <- split_list[[4]]

lessclassifier <- LESSClassifier$new()
lessclassifier$fit(X_train, y_train)

## ------------------------------------------------
## Method `LESSClassifier$predict`
## ------------------------------------------------

preds <- lessclassifier$predict(X_test)
print(caret::confusionMatrix(data=factor(preds), reference = factor(y_test)))

## ------------------------------------------------
## Method `LESSClassifier$get_estimator_type`
## ------------------------------------------------

lessclassifier$get_estimator_type()

## ------------------------------------------------
## Method `LESSClassifier$set_random_state`
## ------------------------------------------------

lessclassifier$set_random_state(2022)