r - Variable Width Bar Plot

Question

I'd like to produce an area/bar graph in R similar to this: (plot from David MacKay's (excellent) book "Sustainable Energy")

I honestly can't even find the proper name for a plot like this. It seems to be a bar graph with variable width bars. Certainty a powerful communication tool.

Answer 1

You can do this with base graphics. First we specify some widths and heights:

widths = c(0.5, 0.5, 1/3,1/4,1/5, 3.5, 0.5)
heights = c(25, 10, 5,4.5,4,2,0.5)

Then we use the standard barplot command, but specify the space between blocks to be zero:

##Also specify colours
barplot(heights, widths, space=0, 
        col = colours()[1:6])

Since we specified widths, we need to specify the axis labels:

axis(1, 0:6)

To add grid lines, use the grid function:

##Look at ?grid to for more control over the grid lines
grid()

and you can add arrows and text manually:

arrows(1, 10, 1.2, 12, code=1)
text(1.2, 13, "A country") 

To add your square in the top right hand corner, use the polygon function:

polygon(c(4,4,5,5), c(20, 25, 25, 20), col="antiquewhite1")
text(4.3, 22.5, "Hi there", cex=0.6)

This all gives:

---

Aside: in the plot shown, I've used the par command to adjust a couple of aspects:

par(mar=c(3,3,2,1), 
    mgp=c(2,0.4,0), tck=-.01,
    cex.axis=0.9, las=1)