Innovations in aesthetic evaluation semantics: Where ggplot2 users and developers meet

Music City Center 

In recent years, the aesthetic evaluation semantics in ggplot2 has evolved into a rich and powerful interface serving the needs of both its users and developers. Taking advantage of R's metaprogramming capabilities, functions like after_stat() and stage() create a shared vocabulary between users and developers that allows them to reason about layer-internal processes at an intermediate level of abstraction. This design pattern exemplifies a paradigm shift in the implementation of the Grammar of Graphics, demonstrating that complexity can be tamed rather than hidden. I demonstrate how ggplot2's innovations in aesthetic evaluation serves a dual purpose: empowering users to grow into developers while enabling developers to create interfaces that evolve with their users.