NEWS

---

rfastloess 3.0.0

Added

• Added case weights to Streaming chunks and Online points, plus current-window Online diagnostics and prediction.
• OnlineLoess() now accepts multivariate coordinate vectors in add_point() when dimensions is greater than one.
• Added an Alternative Software vignette with runnable Gaussian and robust comparisons to stats::loess() and a guide to LOESS-specific defaults.
• Added cv_opts() and the cv argument on Loess() for grouped Batch cross-validation.
• Added outputs to Loess(), StreamingLoess(), OnlineLoess(), and predict.Loess() for grouped optional results with mode-specific name validation.
• Added retain_model and a predict.Loess() S3 method for out-of-sample prediction.
• Added return_gradient to Loess(), StreamingLoess(), and OnlineLoess().
• Added confidence_intervals/prediction_intervals/return_se to StreamingLoess() and OnlineLoess(). OnlineLoess() requires update_mode = "full" or errors. New bound fields on add_point()'s result.

Changed

• Clarified Batch residual_sd as 1.4826 * MAD; Streaming reports the cumulative sample standard deviation of emitted residuals.
• Breaking change: replaced individual return_* output arguments with outputs = c(...) for Batch, Streaming, Online, and prediction.
• Breaking change: replaced flat interval arguments and prediction levels with intervals = intervals_opts(confidence = ..., prediction = ...); CV uses only cv = cv_opts(...) with an outer seed, replacing flat CV arguments and cv_opts(seed = ...). Removed named constructor arguments now error instead of being silently ignored.
• Unavailable diagnostics are now represented as R NA rather than generic NaN values.

Fixed

• Use the fitted model's kernel for unweighted, unpadded one-dimensional linear prediction standard errors without robustness downweighting, with smoothing influence rows and global residual degrees of freedom, including interpolation; align prediction-interval residual scales.
• Correct tied-coordinate interpolation splits and normalized cell geometry, add two-dimensional neighboring-edge blending, and match R's neighborhood rounding near integer span boundaries.
• Preserve zero interpolation subdivision thresholds to match R's small-span cell trees, retaining terminal observation vertices and correcting interpolated fits on small datasets.
• Normalize local case weights by their neighborhood maximum so common scaling cannot turn valid positive weights into an epsilon-triggered unweighted fallback.
• Prevented overflow in even medians, mean/bisquare scales, Batch/Streaming diagnostics and AIC, and local/all-tied weight sums for large finite inputs.
• Reject fractional/overflowing integer and count options before FFI coercion; validate grouped CV/interval lists and numeric vector/matrix shapes; accept integer custom weights.
• Validate case-weight lengths and values before dropping missing observations, so invalid weights on dropped rows are not silently ignored.
• Preserve case weights through sorted CV training subsets and multidimensional predictions. Serial and parallel CV now agree on seeded folds and held-out LOOCV predictions; K-fold counts above the retained observation count are rejected.
• Reject non-positive or non-finite Streaming/Online auto-convergence tolerances. Online auto-convergence requires full updates with robustness iterations.
• Include all observations for Gaussian smoothing and prediction while preserving the k-th-neighbor bandwidth; use the true exponential without an artificial tail floor.
• Correct case-weighted standard errors for direct, unpadded one-dimensional linear fits and retained prediction, with matching serial/parallel local moments. Span-one fits no longer substitute a kernel-free global OLS formula.
• Honor configured zero-weight fallback policies in constant-degree, zero-bandwidth, insufficient-neighbor, and coefficient-fit paths.
• Match R LOESS's even-sample bisquare MAR scale arithmetic, including extremely small residuals, while preserving the centered-MAD fallback.
• Aligned OnlineLoess defaults across the Rust core and bindings: iterations is now 0 with the default update_mode = "incremental"; positive robustness iterations require update_mode = "full".
• Fixed cv_seed silently accepting negative values and reinterpreting them as a huge unsigned seed instead of raising an error. Now validated before the cast.
• Fixed multivariate Batch/Streaming matrix inputs being flattened in R's column-major order; preserve row-wise coordinates. CV seeds now honor the documented full exact-integer range through 2^53, matrix predict_window() queries are rejected instead of being misinterpreted, and plotting multivariate results now returns a clear unsupported-mode error.

rfastloess 2.0.0

Added

Changed

• Updated the R README to be binding-specific instead of using a generic README shared across bindings.
• Moved R documentation from ReadTheDocs to GitHub Pages, served by pkgdown at https://thisisamirv.github.io/loess-project/r/. The ReadTheDocs site no longer includes R-specific content.
• Changed R version dependency to 4.4.0 due to issues with installing Bioconducter packages on R < 4.4.0.

Fixed

• Fixed .cargo/config.toml hardcoding absolute c:/rtools45/... paths for the x86_64-pc-windows-gnu linker and ar tool; it now uses bare tool names resolved via PATH.
• Fixed Windows ARM64 and CRAN source builds that failed while linking the native R library.
• Fixed Loess(fraction = 0.3, 4) incorrectly succeeding: reject_extra_positional_args() counted unnamed arguments but did not check their position, so a single unnamed arg in any non-first slot passed validation. The check now rejects any unnamed argument that is not in position 1.
• Fixed fit() and process_chunk() silently flattening a matrix x and producing a confusing Rust-level length-mismatch error when dimensions was not set to match ncol(x). Both methods now raise an informative error at the R level, naming the dimensions parameter to fix.

rfastloess 1.0.0

Added

• Introduced S3 generics fit(), process_chunk(), finalize(), and add_point(), replacing the previous list-closure API.
• Added a reject_extra_positional_args() helper to reject extra unnamed arguments.

Fixed

• Fixed incorrect URLs in R binding docs.

Changed

• Moved the tutorials/ pages into a new user-guide/use-cases/ section.
• Split Streaming and Online API reference material into dedicated user-guide pages and added runnable vignette examples.
• Breaking: Renamed the smoothed and std_error fields returned by OnlineLoess's add_point() to y and standard_error.
• Added ... to Loess(), StreamingLoess(), and OnlineLoess() to force named arguments for optional parameters.
• Requires R 4.6 or later.
• Expanded roxygen2 @param docs and added a See Also section linking to https://loess.readthedocs.io/.
• Expanded rfastloess-intro.Rmd vignettes.

rfastloess 0.9.0

Added

• Added the R LOESS package with S3 fitting and result methods.