chris
chris

Reputation: 727

Variable Width Bar Plot

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

Upvotes: 17

Views: 13144

Answers (2)

Eric Fail
Eric Fail

Reputation: 7928

Inspired by the code from the blog post I mentioned above,

df <- data.frame(x = c("Alpha", "Beta", "Gamma", "Delta"), width = c(25, 50, 75, 100), height = c(100, 75, 50, 25))
df$w <- cumsum(df$width)
df$wm <- df$w - df$width
df$wt <- with(df, wm + (w - wm)/2)

library(ggplot2)
p  <- ggplot(df, aes(ymin = 0))
p1 <- p + geom_rect(aes(xmin = wm, xmax = w, ymax = height, fill = x))
library(grid) # needed for arrow function
p1 + geom_text(aes(x = wt, y = height * 0.8, label = x)) + 
     theme_bw() + labs(x = NULL, y = NULL) + 
     theme(axis.ticks = element_blank(),axis.text.x = element_blank(), 
     axis.text.y = element_blank(), legend.position = "none") + 
     annotate("text", x = 120, y = 83, label = "a Beta block") + 
     geom_segment(aes(x = 100, y = 80, xend = 80, yend = 75), 
     arrow = arrow(length = unit(0.5, "cm")))

beta blocker

Upvotes: 18

csgillespie
csgillespie

Reputation: 60462

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:

enter image description here


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)

Upvotes: 27

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