R/char2dd.R

In kardinal-eros/vegit: Utilities for Managing the vegsoup-data Repository

#	must avoid non-ASCII character, degree sign is "\u00B0"

char2dd <- function (x, chd = "\u00B0", chm = "\"", chs = "\"\"", NS = TRUE) {
	#	convert to default of char2dms in package sp
	#	gsub will instantly convert to character if it is not already
	x <- gsub("^\\s+|\\s+$", "", x)      # trim both ends
	x <- gsub(",", ".", x, fixed = TRUE) # decimals	
	x <- gsub(chd, "d", x, fixed = TRUE) # degree
	x <- gsub(chm, "'", x, fixed = TRUE) # minutes
	
	#	if second character duplicates minute character
	n <- nchar(chs)
	nn <- unlist(strsplit(chs, "*"))
	
	if (n > 1 & unique(nn) == chm)	
		x <- gsub(paste0(rep("'", n), collapse = ""), "\"", x, fixed = TRUE)
	else
		x <- gsub(chs, "\"", x, fixed = TRUE)	

	#	index if convertable to numeric
	i <- sapply(sapply(x, type.convert, simplify = FALSE), is.numeric)
	x1 <- unlist(x)[i]
	x2 <- unlist(x)[!i]

	#	char2dms for characters only
	if (length(x2) > 0) {
		x2 <- paste0(x2, ifelse(NS, "N", "E"))
		x2 <- char2dms(x2)
	}
	
	#	combine 
	r <- vector("numeric", length(x))
	r[i] <- as.numeric(x1)
	r[!i] <- as.numeric(x2)
	
	return(r)
}