R/xgx_minor_breaks_log10.R

In xgxr: Exploratory Graphics for Pharmacometrics

#' Sets the default minor_breaks for log10 scales
#' 
#' \code{xgx_minor_breaks_log10} sets nice minor_breaks for log10 scale.
#'
#' 
#' @param data_range range of the data
#' 
#' @return numeric vector of breaks
#' 
#' @examples 
#' xgx_minor_breaks_log10(c(1, 1000))
#' xgx_minor_breaks_log10(c(0.001, 100))
#' xgx_minor_breaks_log10(c(1e-4, 1e4))
#' xgx_minor_breaks_log10(c(1e-9, 1e9))
#' xgx_minor_breaks_log10(c(1, 2))
#' xgx_minor_breaks_log10(c(1, 5))
#' xgx_minor_breaks_log10(c(1, 10))
#' xgx_minor_breaks_log10(c(1, 100))
#' xgx_minor_breaks_log10(c(1, 1.01))
#' xgx_minor_breaks_log10(c(1, 1.0001))
#' print(xgx_minor_breaks_log10(c(1, 1.000001)), digits = 10)
#' 
#' @importFrom labeling extended
#' @export
xgx_minor_breaks_log10 <-  function(data_range) {
  r1 <- range(log10(data_range))
  r <-  r1
  r[1] <-  floor(r[1])
  r[2] <-  ceiling(r[2]) + 1
  minor_breaks <- c()
  for (i in seq(r[1], r[2])) {
    minor_breaks <-  c(minor_breaks, seq(2 * 10^(i - 1), 10^i - 10^(i - 1),
                             by = 10^(i - 1)))
  }
  minor_breaks <-  minor_breaks[minor_breaks <= 10^r1[2]]
  minor_breaks <-  minor_breaks[minor_breaks >= 10^r1[1]]
  return(minor_breaks)
}