dms2dec

dms2dec <- function(dms, separators = c("º", "°", "\'", "’", "\"", "\\?")) {
  # separators = c("º", "°", "\'", "’", "\"", "\\?")
  # separators = c("\\u00ba", "\\u00b0", "\\'", "\\u2019", "\"", "\\?", "\\\\?")

  # by A. Marcia Barbosa (https://modtools.wordpress.com/)
  #   contributions by PaulMelloy (https://github.com/PaulMelloy)
  # license: CC BY-SA 4.0 (Creative Commons)
  # like R, this function is free, open-source and comes with absolutely no warranty; bug reports welcome!

  # version 1.6 (27 May 2024)
  # dms: a vector of latitude or longitude in degrees-minutes-seconds-hemisphere,
  #   e.g. 41° 34' 10.956" N (with or without spaces) or
  # ddm: a vector of latitude or longitude in degrees-decimal minutes
  #   e.g. 41° 34.1826' N (with or without spaces)
  # separators: the characters that are separating degrees, minutes and seconds in dms

  # to source this function, remember to add encoding:
  # source("https://raw.githubusercontent.com/AMBarbosa/unpackaged/master/dms2dec", encoding = "UTF-8")

  dms <- as.character(dms)
  dms <- gsub(pattern = " ", replacement = "", x = dms)
  new_split_string <- "_splitHere_"
  for (s in separators) dms <- gsub(pattern = s, replacement = new_split_string, x = dms, useBytes = FALSE)
  dms <- gsub(paste0(new_split_string, new_split_string), new_split_string, dms, useBytes = TRUE)

  splits <- strsplit(dms, split = "_splitHere_")
  n <- length(dms)
  deg <- min <- sec <- hem <- vector("character", n)

  for (i in 1:n) {
    deg[i] <- splits[[i]][1]
    min[i] <- splits[[i]][2]

    # Check if Degrees decimal minutes
    dm <- unlist(strsplit(min[i], "[.]"))
    if (length(dm) > 1) {
      if (length(dm) > 2)
        stop("Input minutes format is not recongnisable")

      sec[i] <- as.numeric(paste0("0.", dm[2], collapse = "")) * 60
      min[i] <- dm[1]
      if(min[i] > 60) stop("minutes entry exceeds 60, check minutes input")

      hem[i] <-
        splits[[i]][splits[[i]] %in% c("N", "S", "E", "W", "n", "s", "e", "w")]

    } else{
      if (length(splits[[i]]) < 4) {
        hem[i] <- splits[[i]][3]
      } else {
        sec[i] <- splits[[i]][3]
        hem[i] <- splits[[i]][4]
      }
    }
  }

  dec <- colSums(rbind(as.numeric(deg), (as.numeric(min) / 60), (as.numeric(sec) / 3600)), na.rm = TRUE)
  sign <- ifelse (hem %in% c("N", "E"), 1, -1)
  hem_miss <- which(is.na(hem))
  if (length(hem_miss) > 0) {
    warning("Hemisphere not specified in position(s) ", hem_miss, ", so the sign of the resulting coordinates may be wrong.")
  }
  dec <- sign * dec
  return(dec)
}  # end dms2dec function