Expand auxiliary features

Add empty columns for auxiliary features.

Usage

.expand_auxiliary(x, primary)

Arguments

x

matrix with \(n\) rows and either \(p_0\) or \(p_0 + p_1\) features

primary

logical vector of length \(p_0 + p_1\) with \(p_0\) entries equal to TRUE (primary features) and \(p_1\) entries equal to FALSE (auxiliary features)

Value

Returns a matrix with \(n\) rows and \(p_0 + p_1\) columns.

See also

This function is called by predict().

Examples

n <- 5L
p <- 10L
x <- matrix(data = rnorm(n * p), nrow = n, ncol = p)
primary <- as.logical(rbinom(n = p, size = 1L, prob = 0.5))
x_primary <- x[, primary]
x_expanded <- .expand_auxiliary(x = x_primary, primary = primary)
all(x_expanded[, primary] == x[, primary])
#> [1] TRUE
all(x_expanded[, !primary] == 0L)
#> [1] TRUE