R/remove-collinear.R

In Alanocallaghan/nalar: Various things I want it to do

remove_collinear <- function(x) {
    combs <- utils::combn(seq_len(ncol(x)), 2)
    collinear <- sapply(
        seq_len(ncol(combs)),
        function(i) {
            compare_columns(x[[combs[1, i]]], x[[combs[2, i]]])
        }
    )
}

compare_columns <- function(a, b) {
    a <- to_numeric(a)
    b <- to_numeric(b)
    length(stats::na.omit(unique(a - b))) == 1
}

to_numeric <- function(x) {
    if (is.character(x)) {
        x <- factor(x)
    }
    if (is.factor(x) || is.logical(x)) {
        x <- as.numeric(x)
    }
    x
}