Extract {hySAINT}

Extracting columns and generating required interaction effects from data

Description

This function simplifies the data preparation process by enabling users to extract specific columns from their dataset X, and automatically generating any necessary interaction effects based on varind.

Usage

Extract(X, varind, interaction.ind = NULL)

Arguments

X

Input data. An optional data frame, or numeric matrix of dimension n observations by p main effects. Note that the interaction effects should not be included in X because this function automatically generates the corresponding interaction effects if needed.

varind

A numeric vector that specifies the indices of variables to be extracted from X. Duplicated values are not allowed. See Example for details.

interaction.ind

A two-column numeric matrix. Each row represents a unique interaction pair, with the columns indicating the index numbers of the variables involved in each interaction. Note that interaction.ind must be generated outside of this function using t(utils::combn(p,2)). See Example section for details.

Value

A numeric matrix is returned.

Examples

# Generate interaction.ind
interaction.ind <- t(combn(4,2))

# Generate data
set.seed(0)
X <- matrix(rnorm(20), ncol = 4)
y <- X[, 2] + rnorm(5)

# Extract X1 and X1X2 from X1, ..., X4
Extract(X, varind = c(1,5), interaction.ind)

# Extract X5 from X1, ..., X4
Extract(X, varind = 5, interaction.ind)

# Extract using duplicated values
try(Extract(X, varind = c(1,1), interaction.ind)) # this will not run