This collection of functions in granovaGG provides what we
call elemental graphics for display of anova results. The term
elemental derives from the fact that each function is aimed at
construction of graphical displays that afford direct
visualizations of data with respect to the fundamental
questions that drive the particular anova methods. This package
represents a modification of the original granova package; the
key change is to use ggplot2, Hadley Wickham's package based on
Grammar of Graphics concepts (due to Wilkinson). The main
function is granovagg.1w (a graphic for one way anova); two
other functions (granovagg.ds and granovagg.contr) are to
construct graphics for dependent sample analyses and
contrast-based analyses respectively. (The function granova.2w,
which entails dynamic displays of data, is not currently part
of granovaGG.) The granovaGG functions are to display data for
any number of groups, regardless of their sizes (however, very
large data sets or numbers of groups can be problematic). For
granovagg.1w a specialized approach is used to construct
data-based contrast vectors for which anova data are displayed.
The result is that the graphics use a straight line to
facilitate clear interpretations while being faithful to the
standard effect test in anova. The graphic results are
complementary to standard summary tables; indeed, numerical
summary statistics are provided as side effects of the graphic
constructions. granovagg.ds and granovagg.contr provide graphic
displays and numerical outputs for a dependent sample and
contrast-based analyses. The graphics based on these functions
can be especially helpful for learning how the respective
methods work to answer the basic question(s) that drive the
analyses. This means they can be particularly helpful for
students and non-statistician analysts. But these methods can
be of assistance for work-a-day applications of many kinds, as
they can help to identify outliers, clusters or patterns, as
well as highlight the role of non-linear transformations of
data. In the case of granovagg.1w and granovagg.ds several
arguments are provided to facilitate flexibility in the
construction of graphics that accommodate diverse features of
data, according to their corresponding display requirements.
See the help files for individual functions.