cowplot_mimic

## functions

plot.histograms <- function(cname="", flip=FALSE, xlim) {

	dse <- density(setosa[, cname])
	dve <- density(versicolor[, cname])
	dvi <- density(virginica[, cname])

	ymax <- max(c(dse$y, dve$y, dvi$y))
	ymin <- min(c(dse$y, dve$y, dvi$y))

	ylim <- c(ymin,ymax)

	mar <- c(0,5,2,0)

	if (flip==TRUE) {
		temp <- dse$x
		dse$x <- dse$y
		dse$y <- temp

		temp <- dvi$x
		dvi$x <- dvi$y
		dvi$y <- temp

		temp <- dve$x
		dve$x <- dve$y
		dve$y <- temp

		temp <- xlim
		xlim <- ylim
		ylim <- temp
		
		mar <- c(5,0,0,2)
	}

	par(mar=mar)
	plot(1,1, pch="", xlim=xlim, ylim=ylim, bty="n", xaxt="n", yaxt="n", xlab="", ylab="")
	lines(dse$x, dse$y)
	polygon(dse$x,  dse$y, col=t_col(cse))
	lines(dve$x, dve$y)
	polygon(dve$x,  dve$y, col=t_col(cve))
	lines(dvi$x, dvi$y)
	polygon(dvi$x,  dvi$y, col=t_col(cvi))
}

t_col <- function(color, percent = 50) {
	#	  color = color name
	#	percent = % transparency
	#	   name = an optional name for the color
	## Get RGB values for named color
  	rgb.val <- col2rgb(color)
	## Make new color using input color as base and alpha set by transparency
  	t.col <- rgb(rgb.val[1], rgb.val[2], rgb.val[3],
              	 max = 255,
              	 alpha = (100-percent)*255/100)

	return(t.col)
}

# plotting code

# split for convenience
setosa     <- iris[iris$Species=="setosa",]
versicolor <- iris[iris$Species=="versicolor",]
virginica  <- iris[iris$Species=="virginica",]

# colours
cse <- "pink2"
cve <- "palegreen3"
cvi <- "dodgerblue1"

# scatter colours
scat.cols <- c(rep(cse, nrow(setosa)), rep(cve, nrow(versicolor)), rep(cvi, nrow(virginica)))

# min and max
minsl <- min(iris$Sepal.Length)
minsw <- min(iris$Sepal.Width)
maxsl <- max(iris$Sepal.Length)
maxsw <- max(iris$Sepal.Width)


png("test.png", height=1200, width=1200)

# layout
layout(matrix(c(1:4), nrow=2, byrow=TRUE), widths=c(0.80,0.20), heights=c(0.20,0.80))

# top histogram
plot.histograms("Sepal.Length", xlim=c(minsl, maxsl))

# empty
plot(1:10,1:10,xlim=xlim, ylim=ylim, bty="n", xaxt="n", yaxt="n", xlab="", ylab="")

# main scatterplot
par(mar=c(5,5,0,0), xaxs="r")
plot(iris$Sepal.Length, iris$Sepal.Width, xlim=c(minsl,maxsl), ylim=c(minsw, maxsw), col=scat.cols, pch=16, cex=4, xlab="Sepal.Length", ylab="Sepal.Width", cex.axis=2, cex.lab=2)

# right histogram
plot.histograms("Sepal.Width", xlim=c(minsw, maxsw), flip=TRUE)

# close PNG device
dev.off()