Is a heatmap in “sized dot style” possible in ggplot2?

Question

Is it possible to draw a heatmap with circles instead of square in ggplot2? It would be neat to not only represent the values by a color gradient but also by the circle size

Answer 1

In this example size and colour both correspond with the variable value because it's the only variable numeric available in the kreuz.m dataset.

ggplot(kreuz.m, aes(Name, variable)) +
  geom_point(aes(size = value, colour=value))