Helpful scales for use with ggplot2

scale_x_hours.r

require(ggplot2)
require(scales)

seq_range <- function(x, by) seq(min(x), max(x), by=by)

time_breaks <- function(width) {
  function(limits) seq_range(limits, by=width)
}

scale_x_hours <- function(
  ..., 
  breaks = date_breaks(width='1 hour'), 
  minor_breaks = time_breaks(width='15 mins'),
  labels = date_format('%H:%M\n%a')
) {
	scale_x_datetime(..., breaks=breaks, minor_breaks=minor_breaks, labels=labels)
}