R/freq.axis.r

In mschemmel/gmap: Visualize genetic/linkage maps

#' Function to determine y axis values
#' 
#' @param maxval Maximum value of frequency in original data frame
#' @importFrom graphics text
#' @export
freq.axis <- function(maxval) {
    roundto = 100
	roundup <- function(maxval, to = roundto) { to*(maxval%/%to + as.logical(maxval%%to)) }
			
	scalerange = seq(100,1000,900/(roundup(maxval)/roundto))	
	scalelabels = rev(seq(0,roundup(maxval), roundto)) 	
	
	# show main vertical scale line	
	#segments(x0 = -1, 
	#		 y0 = 0,
	#		 x1 = -1,
	#		 y1 = 1000,
	#		 col = "black")
	
	# show ticks
	#segments(x0 = -1,
    #         y0 = scalerange, 
    #         x1 = -10, 
    #         y1 = scalerange,
    #         col = "black")
	
	# show axis labels
    text(-10, scalerange, scalelabels, cex = .8)	
}