This page aims to describe how to realise a basic circle packing chart with only one level of hierarchy. Basically, you just represent each entity or individual of your dataset with a circle, its size depends of a provided value.
Calculating the arrangement of dots is not a trivial problem. To resolve it, we use the packcircles library that will calculate the coordinates of every points of the circle edges. Then, we use ggplot2 to plot these shapes!
# Create data
data=data.frame(group=paste("Group", letters[1:20]), value=sample(seq(1,100),20))
# Generate the layout. This function return a dataframe with one line per bubble.
# It gives its center (x and y) and its radius, proportional of the value
packing <- circleProgressiveLayout(data$value, sizetype='area')
# We can add these packing information to the initial data frame
data = cbind(data, packing)
# Check that radius is proportional to value. We don't want a linear relationship, since it is the AREA that must be proportionnal to the value
# The next step is to go from one center + a radius to the coordinates of a circle that
# is drawn by a multitude of straight lines.
dat.gg <- circleLayoutVertices(packing, npoints=50)
# Make the plot
# Make the bubbles
geom_polygon(data = dat.gg, aes(x, y, group = id, fill=as.factor(id)), colour = "black", alpha = 0.6) +
# Add text in the center of each bubble + control its size
geom_text(data = data, aes(x, y, size=value, label = group)) +
scale_size_continuous(range = c(1,4)) +
# General theme:
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