robscale 0.2.1

• Performance: Refined runtime SIMD dispatch for qn() and sn() kernels, achieving optimal vectorization across x86_64 (AVX2/FMA) and ARM64 (NEON).
• New feature: scale_robust() provides a unified dispatcher that automatically selects between a variance-weighted ensemble of 7 estimators (for small samples) and the Gini Mean Difference (GMD) for larger samples (n >= 20).
• New estimators: Added gmd(), iqr_scaled(), mad_scaled(), and sd_c4() to the public API.
• Confidence Intervals: Added ci = TRUE to all scale estimators, providing analytical intervals (GMD, MAD, Sn, Qn, bias-corrected SD) or bootstrap-based intervals (ensemble).
• Performance: Replaced stats::mad() and stats::IQR() with optimized C++ implementations (mad_scaled(), iqr_scaled()) using O(n) selection via the pdqselect algorithm.
• Documentation: Expanded README with detailed benchmarking vs. robustbase, Hmisc, GiniDistance, and collapse.
• Citations: Consolidated and updated all package citations in inst/CITATION and documentation.

robscale 0.1.6

• Performance: Extended optimal sorting networks from n <= 8 to n <= 16 using Dobbelaere’s verified optimal networks. Cross-platform benchmarking confirmed 2-4x speedups over std::sort for n = 9-16 on both ARM64 (Apple Silicon) and x86_64 (AMD Zen 3).
• Bug fix: Corrected the n = 7 sorting network comparator sequence (was producing incorrect sort order for certain inputs).
• Bug fix: Restored ADM consistency constant to sqrt(pi/2) = 1.2533 (was incorrectly changed to 1.3926).
• Bug fix: Restored small-sample fallback logic in robScale() that was inadvertently removed, causing incorrect results when MAD collapses for n < 4.

robscale 0.1.5

• CRAN: Removed #pragma GCC diagnostic ignored "-Wdeprecated-volatile" from src/qn_estimator.cpp, src/sn_estimator.cpp, and src/qnsn_sort_utils.h to resolve the “pragmas suppressing diagnostics” NOTE requested by CRAN maintainers.
• Windows: Added configure.win and cleanup.win to suppress spurious win-builder warnings about missing Windows configuration.
• CI: Added GitHub Actions R-CMD-check workflow with multi-platform matrix (Windows, macOS, Ubuntu) as independent evidence of Windows compilation.
• Portability: Fixed uninitialized NEON register in qnsn_kernels.h that Clang 17 on macOS promoted to a compilation WARNING.
• Build: Switched RcppParallel::LdFlags() to the canonical RcppParallel::RcppParallelLibs() in Makevars.win and Makevars.in.

robscale 0.1.4

• Portability: Fixed macOS (Apple Silicon) compilation error by switching to the more portable <Accelerate/Accelerate.h> include and resolving a symbol conflict with R’s COMPLEX type.
• Portability: Restored explicit CXX_STD = CXX17 in Makevars (required by CRAN policy for packages using C++17 features).
• Portability: Removed non-portable GCC pragmas to silence warnings on Clang (win-builder Debian).
• CRAN: Retained GNU make in SystemRequirements ($(shell) is a GNU extension used for RcppParallel linking).
• CRAN: Added inst/WORDLIST to whitelist technical terms from aspell.
• CRAN: Quoted ‘Qn’ and ‘Sn’ in DESCRIPTION to satisfy metadata checks.
• Build: Resolved duplicate -ltbb flag from Makevars which caused warnings on some macOS configurations.

robscale 0.1.3

• Added high-efficiency scale estimators: qn() and sn() (Rousseeuw & Croux, 1993) with specialized sorting network kernels and cache-aware parallelization.
• Added robustbase to Suggests for reference and benchmarking.
• Added documentation examples for all five exported functions.
• Performance optimizations: configure script auto-detects SIMD capabilities (AVX2/FMA on x86_64, NEON on ARM64) without requiring any environment variables.

robscale 0.1.1

• Consistent NA handling: adm() now raises an error when na.rm = FALSE and NAs are present, matching robLoc() and robScale() behavior.
• Replaced manual new[]/delete[] with std::unique_ptr for RAII memory safety in all C++ estimator functions.
• Removed unused scoring-iteration constants (PSI_NORM_CONST, INV_PSI_NORM_CONST) from robust_core.h.
• Hoisted loop-invariant half_inv_s above the Newton–Raphson loop in rob_loc.cpp.
• Added Mermaid algorithm flowcharts for robLoc and robScale to README.
• Expanded test suite: explicit-center tests for adm(), maxit edge cases for robLoc() and robScale(), sorting network verification for n = 2–8.
• Added cph role to Authors@R in DESCRIPTION.

robscale 0.1.0

Initial release.

• Three functions: adm(), robLoc(), and robScale() implementing the robust location and scale M-estimators of Rousseeuw & Verboven (2002) for very small samples.
• API-compatible drop-in replacement for the revss package.
• C++17 implementation via Rcpp with:
  • Newton–Raphson iteration for location (quadratic convergence).
  • Algebraic tanh(x/2) identity for the logistic psi function with platform-vectorized bulk evaluation (Apple Accelerate on macOS, OpenMP SIMD hints on Linux).
  • Floyd–Rivest O(n) selection for median computation.
  • Optimal sorting networks for n <= 8.
  • Stack-allocated arena buffers (zero heap allocation for n <= 512).
• Numerical equivalence with revss verified across 5,400 systematic comparisons (tolerance: sqrt(.Machine$double.eps)).