Changelog

Source: NEWS.md

clustOpt 1.2

New features

• Added KL divergence (calculate_kl_divergence()) and Hellinger distance (calculate_hellinger_distance()) metrics for evaluating cluster distribution consistency between training and held-out subjects.
• Added modularity score (calculate_modularity()) computed on the precomputed SNN graph.
• Added MSE and MAD scores (calculate_mse_score()) for centroid-based cluster quality evaluation.
• New suggest_resolution() function that ranks resolutions using two complementary methods: direct rank aggregation across four metrics, and curvature-based local optima detection via second-order finite differences.
• New summarize_cv_metrics() for per-resolution metric summaries.
• New visualization functions plot_rank_metrics() and plot_mean_rank().
• Logging improvements to make clustOpt messages distinct from its dependencies.

Performance improvements

• Pre-allocate the results list in the main cross-validation loop instead of growing it with c(), reducing memory allocation overhead for many subjects.
• Use crossprod() instead of explicit t() %*% in PCA projections, avoiding materialization of transposed gene-by-cell matrices.
• Use Matrix::crossprod() in modularity calculation to stay in sparse matrix space and avoid dense transposition of the cluster indicator matrix.
• Replace do.call(rbind, lapply(...)) with t(vapply(...)) in MAD calculation to avoid intermediate list allocation.
• Precompute SNN graph and distance matrix once per held-out subject (shared across resolutions) instead of recomputing per resolution.
• Pre-extract cluster assignments from metadata by resolution to avoid repeated column lookups.

Logging and verbosity

• verbose parameter now accepts integer levels (0-3) for fine-grained control: 0 = silent, 1 = key milestones, 2 = detailed progress, 3 = Seurat output.
• Backward-compatible: verbose = TRUE maps to level 1, FALSE to 0.
• Added per-step timing via [step_name] Xs log messages at verbose >= 1.

Bug fixes

• Fixed flipped sign in KL divergence calculation.
• Fixed ARI estimate for comparing singleton clusters.
• Handled edge cases in sample validation and metric computation.

Package reorganization

• Split monolithic clustOpt.R and utils.R into focused modules: clust_opt.R, data_preparation.R, metrics.R, sketching.R, validation.R, visualization.R.
• Removed vignette build cache from version control.

clustOpt 1.1

• Added additional clustering metrics.

clustOpt 1.0

• Initial public release with subject-wise cross-validation, leverage score sketching, BPCells on-disk support, and silhouette-based evaluation.