R/utils-tourr.R

In uschiLaa/galahr: galahr: A GUI to assist learning about high dimensions in R

# functions below are utility functions copied from tourr


# Compute maximum distance from data to origin.
#
# @keywords internal
max_dist <- function(data, center = FALSE) {
  max(sqrt(rowSums(data ^ 2)))
}

# Compute half range measure used for plots.
#
# @keywords internal
compute_half_range <- function(half_range, data, center) {
  if (!is.null(half_range)) return(half_range)

  if (center) {
    data <- center(data)
  }
  half_range <- max_dist(data, center)
  message("Using half_range ", format(half_range, digits = 2))
  half_range
}

# Center the data.
#
# @keywords internal
center <- function (x) 
{
  scale(x, center = TRUE, scale = FALSE)
}