Scagnostics

Leland Wilkinson, SPSS Inc. and Northwestern University

Scagnostics is a Tukey neologism for the term "scatterplot diagnostics." Scagnostics define characterizations of the 2D distributions of orthogonal pairwise projections of a set of points in multidimensional Euclidean space. These characterizations include such measures as density, skewness, shape, outliers, and texture. We introduce a set of scagnostics measures based on graph theory and we analyze their distributions and performance.