This R package provides a comprehensive suite of tools for the analysis and visualization of asymmetric data using Multidimensional Scaling (MDS) and related decomposition techniques. Asymmetry is a common challenge in social sciences, marketing, and sensory research, where the relationship from object \(i\) to \(j\) does not necessarily equal the relationship from \(j\) to \(i\). The package implements several specialized models to capture these directional differences:
ASYMSCAL: A weighted MDS model that accounts for asymmetry through differential weighting of dimensions, estimated via the SMACOF (Scaling by Majorizing a Complicated Function) framework.
MDS with Unique Dimensions: An extension that identifies specific dimensions or “uniqueness” values unique to individual rows or columns within a distance matrix.
Slide-vector Model: A method that models asymmetry by adding a directional “slide” vector to a symmetric configuration, representing a shared bias or trend in the data.
Skew-symmetric Decomposition: Tools to decompose a square matrix into its symmetric and skew-symmetric components (\(S\) and \(A\)), including singular value decomposition (SVD) of the skew-symmetric part for low-dimensional representation. Beyond model fitting, the package includes robust diagnostic and visualization functions. It offers heatmap visualizations for dominance relations, as well as specialized plot methods for configurations, slide-vectors, and skew-symmetric planes.