##############################################################
# 
# R FUNCTION "DECIMAL", TO OUTPUT A REAL NUMBER TO A SPECIFIED
#   NUMBER OF DECIMAL POINTS INCLUDING TRAILING ZEROES.
# 
# BY JEFFREY S. ROSENTHAL (www.probability.ca), January 2025
#
# USAGE: decimal(r,i) to output the real value r with i decimal points.
#
# FLAGS: per=TRUE to write as percentage and append "%"
#        texper=TRUE to write as percentage and append "\\%"
#				(for inclusion in a tex document)
#
# EXAMPLES:
# decimal(5.31, 1)  ## Returns "5.3"
# decimal(5.31, 4)  ## Returns "5.3100"
# decimal(0.531, 2, per=TRUE)  ## Returns "53.10%"
# decimal(0.531, 2, texper=TRUE)  ## Returns "53.10\\%"

decimal = function(x, numdec=1, per=FALSE, texper=FALSE) {
  if (per || texper)
    xx = x * 100.0
  else
    xx = x
  check.integer = function(xx) {abs(xx - round(xx)) < 10^(-8)}
  extratext = ""
  if (check.integer(xx) && (numdec >= 1) )
    extratext = "."
  for (d in 1:floor(numdec)) {
    if (check.integer(xx * 10^(d-1)))
      extratext = paste(extratext, "0", sep="")
  }
  if (texper)
    extratext = paste(extratext, "\\%", sep="")
  else if (per)
    extratext = paste(extratext, "%", sep="")
  return(paste(round(xx,numdec), extratext, sep=""))
}