categorize {cases}

Categorize continuous values

Description

This function allows to split continuous values, e.g. (risk) scores or (bio)markers, into two or more categories by specifying one or more cutoff values.

Usage

categorize(
  values,
  cutoffs = rep(0, ncol(values)),
  map = 1:ncol(values),
  labels = NULL
)

Arguments

values

numeric matrix of continuous values to be categorized. Assume an (n x r) matrix with n observations (subjects) of r continuous values.

cutoffs

numeric matrix of dimension m x k. Each row of cutoffs defines a split into k+1 distinct categories. Each row must contain distinct values. In the simplest case, cutoffs is a single column matrix whereby is row defines a binary split (<=t vs. >t). In this case (k=1), cutoffs can also be a numeric vector.

map

integer vector of length k with values in 1:r, whereby r = ncol(values). map_l gives the value which column of values should be categorized by ...

labels

character of length m (= number of prediction r)

Value

numeric (n x k) matrix with categorical outcomes after categorizing.

Examples

set.seed(123)
M <- as.data.frame(mvtnorm::rmvnorm(20, mean=rep(0, 3), sigma=2*diag(3)))
M
categorize(M)
C <- matrix(rep(c(-1, 0, 1, -2, 0, 2), 3), ncol=3, byrow = TRUE)
C
w <- c(1, 1, 2, 2, 3, 3)
categorize(M, C, w)