R/unique_labels.R

In MetabolomicsBasics: Basic Functions to Investigate Metabolomics Data Matrices

#' @title unique_labels.
#' @description \code{unique_labels} will generate a dataframe with color and
#'   plotting character specification out of a sample table definition.
#' @details If a color/symbol specification exists for a sample set containing
#'   replicate groups this function will help in retrieving this information
#'   per group which is useful in boxplot or legend functions (cf. examples).
#' @param sam Sample table.
#' @param g Either column name from sam containing factor column or factor of same length as sam.
#' @return Dataframe with group levels names and their color and plotting character specification.
#' @examples
#' sam <- MetabolomicsBasics::sam
#' unique_labels(sam = sam, g = "GT")
#' @export
unique_labels <- function(sam = NULL, g = NULL) {
  stopifnot(c("pchs", "cols") %in% colnames(sam))
  if (length(g) == 1 && is.character(g) && g %in% colnames(sam)) {
    g <- factor(unlist(sam[, g]))
  }
  stopifnot(is.factor(g) & length(g) == nrow(sam))
  tmp <- data.frame(
    "Level" = levels(g),
    "pchs" = sapply(split(sam[, "pchs"], g), function(x) {
      sort(unique(x))[1]
    }),
    "cols" = sapply(split(sam[, "cols"], g), function(x) {
      sort(unique(x))[1]
    }),
    stringsAsFactors = FALSE
  )
  return(tmp)
}