Heatmaps are a common tool for visualizing gene expression patterns produced by
high throughput technologies such as microarrays. Here I demonstrate how to
produce the following heatmap in R using the ggplot2 package.
The colour scheme for this heatmap is colour-blind friendly and was developed
based on how individuals interpret colour. To create the above heatmap, we first
generate some example expression data:
Before plotting the data, we must first melt it into the format that ggplot2
expects (see tidy data). We then plot and save the resulting image using ggplot2.