Version 0.9.0 of the ggplot2 package contains a number of changes that provide a user with
more flexibility and greater ease of use in the construction of a ggplot. The two most evident
improvements from a user’s perspective are: (i) the help pages have been expanded considerably,
with many new examples; and (ii) the computing time has been reduced significantly.
Several new geoms are introduced, as well as a few new stat_ functions. These will be described
in the sections to follow.
This version marks the inception of a renovation project designed to off-load groups of
related functions into separate packages and streamlining the code to produce a more consistent
user interface across those sets of functions. The scales package is the first evidence of this
process, but others will follow in due course. Another important decision made in this processis to gradually rewrite the core code of the package in S3, which is anticipated to have two
important effects: (i) faster execution of code; (ii) greater participation from ggplot2 users
in the development of the package. Moreover, steps have been taken to initiate rigorous unit
testing to ensure that new and/or revised code is performing as expected, with the aim of
reducing the probability of bugs in the future and faster response time in fixing bugs should
they occur. This redesign is part of an effort to transition from a single-developer project to a
user community project.
This document is an extension of the NEWS files in the ggplot2 and scales packages, describing
the changes and new features in some detail, in the hope that it will ease the transition
for existing ggplot2 users. The changes that will most directly affect users in this version have
to do with guides–specifically, positional axes, text annotation and legends.