Differential Abundance Analysis for Phosphoproteomics Data // Provides tools for analyzing differential abundance in proteomics experiments. Implements S3 classes for data management and supports Generalized Linear Models (GLM; Nelder and Wedderburn (1972) doi:10.2307/2344614), Aligned Rank Transform (ART; Wobbrock et al. (2011) doi:10.1145/1978942.1978963), and pairwise test methods for statistical analysis. Includes visualization functions for Principal Component Analysis (PCA), volcano plots, and heatmaps.