cool_survival <- function(data = data_frame, time = time, censor = censor, group = group){
	require(survival)
	require(ggfortify)
	fit <- survfit(Surv(time, censor) ~ group, data = data)
	plot_data <- fortify(fit, surv.connect = TRUE)
	plot <- ggplot(plot_data, aes(x = time, y = surv * 100)) + 
		# plot the survival curve(s)
		geom_step(aes(colour = strata), size = 2) + 
		# add the censor indicators
		geom_point(data = subset(plot_data, n.censor > 0), shape = 3, size = 3, stroke = 2, aes(colour = strata)) + 
		# add confidence intervals using the stepribbon geom in the RcmdrPlugin.KMggplot2 package
		RcmdrPlugin.KMggplot2::geom_stepribbon(data = plot_data, 
			aes(x = time, ymin = lower * 100, ymax = upper * 100, fill = strata), 
			alpha = 0.15, colour = "transparent", show.legend = FALSE, kmplot = TRUE) + 
		# set the colours of the confidence intervals
		scale_fill_manual(values = c("steelblue", "darkorange")) +
		# set the colours of the survival curves
		scale_colour_manual(values = c("steelblue", "darkorange"), name = "Hip") + 
		# apply a theme based on the Roboto font size 16
		theme_bw(base_size = 16, base_family = "Roboto") +
		# add a title, x label, y label and footnote
		labs(title = "Custom Made Survival Curve",
			subtitle = "with ggfortify and ggplot2",
     	  x = "Time [years]",
     	  y = "Survival Probability [%]",
     	  caption = "countcool.com") +
 		# set the caption to a smaller italic font in darkolivergreen colour
    	theme(plot.caption = element_text(colour = "darkolivegreen", face = "italic", size = 10)) +
  		# set the y axis limit in steps of 20 %
  		scale_y_continuous(breaks = seq(0, 100, 20)) +
  		# set the x axis in steps of 2 years
  		scale_x_continuous(breaks = seq(0, max(plot_data$time) + 2, 2)) +
  		# add numbers at risk when failed (label creates a border)
		annotate(geom = "label", x = subset(plot_data$time, plot_data$n.censor == 0), 
			y = -15, label = subset(plot_data$n.risk, plot_data$n.censor == 0)) +
		annotate(geom = "text", x = 0.2, y = -8, label = "At Risk", fontface = "italic")
	return(plot)
}