ggproto classes created and adapted for gggda

gggda introduces several ggproto classes for coordinate systems, statistical transformations, and geometric constructions specific to multivariate analysis or following geometric data analysis principles.

Details

The new ggprotos are inspired by two entangled but distinct threads in multivariate data visualization: First, several geometric constructions have been proposed to generalize both numeric and graphical summaries of univariate data to the bivariate setting. Among these are various "peeling" procedures like that by successive convex hulls, which generalize the concept of rank (Green, 1981); and the depth-based bag-and-bolster plot, designed as a bivariate analog of the box-and-whisker plot (Rousseeuw &al, 1999). Second, the use of biplots to visualize singular value–decomposed data benefits from being able to encode variables with different graphical elements than the markers used to encode cases—for example, vectors (arrows emanating from the origin; Gabriel, 1971), calibrated axes (Gower & Hand, 1996), and prediction regions (Gardner & le Roux, 2002).

References

Green PJ (1981) "Peeling Bivariate Data". Interpreting Multivariate Data Chapter 1, 3–19. John Wiley & Sons, Ltd, ISBN 978-0-471-28039-2.

Rousseeuw PJ, Ruts I, & Tukey JW (1999) "The Bagplot: A Bivariate Boxplot". The American Statistician, 53(4): 382–387. doi:10.1080/00031305.1999.10474494

Gabriel KR (1971) "The biplot graphic display of matrices with application to principal component analysis". Biometrika 58(3), 453–467. doi:10.1093/biomet/58.3.453

Gower JC & Hand DJ (1996) Biplots. Chapman & Hall, ISBN: 0-412-71630-5.

Gardner S, le Roux N (2002) "Biplot Methodology for Discriminant Analysis Based upon Robust Methods and Principal Curves". Classification, Clustering, and Data Analysis: Recent Advances and Applications: 169–176. https://link.springer.com/chapter/10.1007/978-3-642-56181-8_18

See also

ggplot2::ggplot2-ggproto and ggplot2::ggproto for explanations of base ggproto classes in ggplot2 and how to create new ones.