Metacoder: An R package for visualization and manipulation of community taxonomic diversity data
Fig 7
Another alternate use example: Visualizing gene expression data in a GO hierarchy.
The gene ontology for all differentially expressed genes in a study on the effect of a glucocorticoid on airway smooth muscle tissue [19]. Color indicates the sign and intensity of averaged changes in gene expression and the size indicates the number of genes classified by a given gene ontology term.