OTReg: Train the ensemble of optimal trees for regression.

Description Usage Arguments Details Value Note Author(s) References See Also Examples

View source: R/OTReg.R

Description

This function selects optimal trees for regression from a total of t.initial trees grown by random forest. Number of trees in the initial set, t.initial, is specified by the user. If not specified then the default t.initial = 1000 is used.

Usage

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OTReg(XTraining, YTraining, p = 0.2, t.initial = NULL,
      nf = NULL, ns = NULL, info = TRUE)

Arguments

XTraining

An n x d dimensional training data matrix/frame consiting of traing observation where n is the number of observations and d is the number of features.

YTraining

A vector of length n consisting of the values of the continuous response variable for the training data.

p

Percent of the best t.initial trees to be selected on the basis of performance on out-of-bag observations.

t.initial

Size of the initial set of regression trees.

nf

Number of features to be sampled for spliting the nodes of the trees. If equal to NULL then the default sqrt(number of features) is executed.

ns

Node size: Minimal number of samples in the nodes. If equal to NULL then the default 5 is executed.

info

If TRUE, displays processing information.

Details

Large values are recommended for t.initial for better performance as possible under the available computational resources.

Value

A trained object consisting of the selected trees for regression.

Note

Prior action needs to be taken in case of missing values as the fuction can not handle them at the current version.

Author(s)

Zardad Khan <zkhan@essex.ac.uk>

References

Khan, Z., Gul, A., Perperoglou, A., Miftahuddin, M., Mahmoud, O., Adler, W., & Lausen, B. (2019). Ensemble of optimal trees, random forest and random projection ensemble classification. Advances in Data Analysis and Classification, 1-20.

Liaw, A. and Wiener, M. (2002) “Classification and regression by random forest” R news. 2(3). 18–22.

See Also

Predict.OTReg, OTProb, OTClass

Examples

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# Load the data

  data(Galaxy)
  data <- Galaxy
  
#Divide the data into training and test parts

  set.seed(9123) 
  n <- nrow(data)
  training <- sample(1:n,round(2*n/3))
  testing <- (1:n)[-training]
  X <- data[,1:4]
  Y <- data[,5]
  
#Train OTReg on the training data

  Opt.Trees <- OTReg(XTraining=X[training,],YTraining = Y[training],t.initial=200)
  
#Predict on test data

  Prediction <- Predict.OTReg(Opt.Trees, X[testing,],YTesting=Y[testing])
  
#Objects returned

  names(Prediction)
  Prediction$Unexp.Variations
  Prediction$Pr.Values
  Prediction$Trees.Used

OTE documentation built on April 20, 2020, 5:05 p.m.