Create Compact Letter Display (CLD) for Statistical Comparisons
Creates compact letter displays (CLDs) for pairwise comparisons from statistical post-hoc tests. Groups sharing the same letter are not significantly different from each other. Supports multiple input formats including results from 'stats' pairwise tests, 'DescTools', 'PMCMRplus', 'rstatix', symmetric matrices of p-values, and data frames. Provides a consistent interface for visualizing statistical groupings across different testing frameworks.